add makefile and pandoc style

Makefile

+1_understanding_a_computer.html: 1_understanding_a_computer.md pandoc.css
+	pandoc -s --toc -c pandoc.css 1_understanding_a_computer.md -o 1_understanding_a_computer.html

pandoc.css

+/*! normalize.css v2.1.3 | MIT License | git.io/normalize */
+
+/* ==========================================================================
+   HTML5 display definitions
+   ========================================================================== */
+
+/**
+ * Correct `block` display not defined in IE 8/9.
+ */
+
+article,
+aside,
+details,
+figcaption,
+figure,
+footer,
+header,
+hgroup,
+main,
+nav,
+section,
+summary {
+    display: block;
+}
+
+/**
+ * Correct `inline-block` display not defined in IE 8/9.
+ */
+
+audio,
+canvas,
+video {
+    display: inline-block;
+}
+
+/**
+ * Prevent modern browsers from displaying `audio` without controls.
+ * Remove excess height in iOS 5 devices.
+ */
+
+audio:not([controls]) {
+    display: none;
+    height: 0;
+}
+
+/**
+ * Address `[hidden]` styling not present in IE 8/9.
+ * Hide the `template` element in IE, Safari, and Firefox < 22.
+ */
+
+[hidden],
+template {
+    display: none;
+}
+
+/* ==========================================================================
+   Base
+   ========================================================================== */
+
+/**
+ * 1. Set default font family to sans-serif.
+ * 2. Prevent iOS text size adjust after orientation change, without disabling
+ *    user zoom.
+ */
+
+html {
+    font-family: sans-serif; /* 1 */
+    -ms-text-size-adjust: 100%; /* 2 */
+    -webkit-text-size-adjust: 100%; /* 2 */
+}
+
+/**
+ * Remove default margin.
+ */
+
+body {
+    margin: 0;
+}
+
+/* ==========================================================================
+   Links
+   ========================================================================== */
+
+/**
+ * Remove the gray background color from active links in IE 10.
+ */
+
+a {
+    background: transparent;
+}
+
+/**
+ * Address `outline` inconsistency between Chrome and other browsers.
+ */
+
+a:focus {
+    outline: thin dotted;
+}
+
+/**
+ * Improve readability when focused and also mouse hovered in all browsers.
+ */
+
+a:active,
+a:hover {
+    outline: 0;
+}
+
+/* ==========================================================================
+   Typography
+   ========================================================================== */
+
+/**
+ * Address variable `h1` font-size and margin within `section` and `article`
+ * contexts in Firefox 4+, Safari 5, and Chrome.
+ */
+
+h1 {
+    font-size: 2em;
+    margin: 0.67em 0;
+}
+
+/**
+ * Address styling not present in IE 8/9, Safari 5, and Chrome.
+ */
+
+abbr[title] {
+    border-bottom: 1px dotted;
+}
+
+/**
+ * Address style set to `bolder` in Firefox 4+, Safari 5, and Chrome.
+ */
+
+b,
+strong {
+    font-weight: bold;
+}
+
+/**
+ * Address styling not present in Safari 5 and Chrome.
+ */
+
+dfn {
+    font-style: italic;
+}
+
+/**
+ * Address differences between Firefox and other browsers.
+ */
+
+hr {
+    -moz-box-sizing: content-box;
+    box-sizing: content-box;
+    height: 0;
+}
+
+/**
+ * Address styling not present in IE 8/9.
+ */
+
+mark {
+    background: #ff0;
+    color: #000;
+}
+
+/**
+ * Correct font family set oddly in Safari 5 and Chrome.
+ */
+
+code,
+kbd,
+pre,
+samp {
+    font-family: monospace, serif;
+    font-size: 1em;
+}
+
+/**
+ * Improve readability of pre-formatted text in all browsers.
+ */
+
+pre {
+    white-space: pre-wrap;
+}
+
+/**
+ * Set consistent quote types.
+ */
+
+q {
+    quotes: "\201C" "\201D" "\2018" "\2019";
+}
+
+/**
+ * Address inconsistent and variable font size in all browsers.
+ */
+
+small {
+    font-size: 80%;
+}
+
+/**
+ * Prevent `sub` and `sup` affecting `line-height` in all browsers.
+ */
+
+sub,
+sup {
+    font-size: 75%;
+    line-height: 0;
+    position: relative;
+    vertical-align: baseline;
+}
+
+sup {
+    top: -0.5em;
+}
+
+sub {
+    bottom: -0.25em;
+}
+
+/* ==========================================================================
+   Embedded content
+   ========================================================================== */
+
+/**
+ * Remove border when inside `a` element in IE 8/9.
+ */
+
+img {
+    border: 0;
+}
+
+/**
+ * Correct overflow displayed oddly in IE 9.
+ */
+
+svg:not(:root) {
+    overflow: hidden;
+}
+
+/* ==========================================================================
+   Figures
+   ========================================================================== */
+
+/**
+ * Address margin not present in IE 8/9 and Safari 5.
+ */
+
+figure {
+    margin: 0;
+}
+
+/* ==========================================================================
+   Forms
+   ========================================================================== */
+
+/**
+ * Define consistent border, margin, and padding.
+ */
+
+fieldset {
+    border: 1px solid #c0c0c0;
+    margin: 0 2px;
+    padding: 0.35em 0.625em 0.75em;
+}
+
+/**
+ * 1. Correct `color` not being inherited in IE 8/9.
+ * 2. Remove padding so people aren't caught out if they zero out fieldsets.
+ */
+
+legend {
+    border: 0; /* 1 */
+    padding: 0; /* 2 */
+}
+
+/**
+ * 1. Correct font family not being inherited in all browsers.
+ * 2. Correct font size not being inherited in all browsers.
+ * 3. Address margins set differently in Firefox 4+, Safari 5, and Chrome.
+ */
+
+button,
+input,
+select,
+textarea {
+    font-family: inherit; /* 1 */
+    font-size: 100%; /* 2 */
+    margin: 0; /* 3 */
+}
+
+/**
+ * Address Firefox 4+ setting `line-height` on `input` using `!important` in
+ * the UA stylesheet.
+ */
+
+button,
+input {
+    line-height: normal;
+}
+
+/**
+ * Address inconsistent `text-transform` inheritance for `button` and `select`.
+ * All other form control elements do not inherit `text-transform` values.
+ * Correct `button` style inheritance in Chrome, Safari 5+, and IE 8+.
+ * Correct `select` style inheritance in Firefox 4+ and Opera.
+ */
+
+button,
+select {
+    text-transform: none;
+}
+
+/**
+ * 1. Avoid the WebKit bug in Android 4.0.* where (2) destroys native `audio`
+ *    and `video` controls.
+ * 2. Correct inability to style clickable `input` types in iOS.
+ * 3. Improve usability and consistency of cursor style between image-type
+ *    `input` and others.
+ */
+
+button,
+html input[type="button"], /* 1 */
+input[type="reset"],
+input[type="submit"] {
+    -webkit-appearance: button; /* 2 */
+    cursor: pointer; /* 3 */
+}
+
+/**
+ * Re-set default cursor for disabled elements.
+ */
+
+button[disabled],
+html input[disabled] {
+    cursor: default;
+}
+
+/**
+ * 1. Address box sizing set to `content-box` in IE 8/9/10.
+ * 2. Remove excess padding in IE 8/9/10.
+ */
+
+input[type="checkbox"],
+input[type="radio"] {
+    box-sizing: border-box; /* 1 */
+    padding: 0; /* 2 */
+}
+
+/**
+ * 1. Address `appearance` set to `searchfield` in Safari 5 and Chrome.
+ * 2. Address `box-sizing` set to `border-box` in Safari 5 and Chrome
+ *    (include `-moz` to future-proof).
+ */
+
+input[type="search"] {
+    -webkit-appearance: textfield; /* 1 */
+    -moz-box-sizing: content-box;
+    -webkit-box-sizing: content-box; /* 2 */
+    box-sizing: content-box;
+}
+
+/**
+ * Remove inner padding and search cancel button in Safari 5 and Chrome
+ * on OS X.
+ */
+
+input[type="search"]::-webkit-search-cancel-button,
+input[type="search"]::-webkit-search-decoration {
+    -webkit-appearance: none;
+}
+
+/**
+ * Remove inner padding and border in Firefox 4+.
+ */
+
+button::-moz-focus-inner,
+input::-moz-focus-inner {
+    border: 0;
+    padding: 0;
+}
+
+/**
+ * 1. Remove default vertical scrollbar in IE 8/9.
+ * 2. Improve readability and alignment in all browsers.
+ */
+
+textarea {
+    overflow: auto; /* 1 */
+    vertical-align: top; /* 2 */
+}
+
+/* ==========================================================================
+   Tables
+   ========================================================================== */
+
+/**
+ * Remove most spacing between table cells.
+ */
+
+table {
+    border-collapse: collapse;
+    border-spacing: 0;
+}
+
+.go-top {
+position: fixed;
+bottom: 2em;
+right: 2em;
+text-decoration: none;
+background-color: #E0E0E0;
+font-size: 12px;
+padding: 1em;
+display: inline;
+}
+
+/* Github css */
+
+html,body{        margin: auto;
+    padding-right: 1em;
+    padding-left: 1em;
+    max-width: 44em; color:black;}*:not('#mkdbuttons'){margin:0;padding:0}body{font:13.34px helvetica,arial,freesans,clean,sans-serif;-webkit-font-smoothing:subpixel-antialiased;line-height:1.4;padding:3px;background:#fff;border-radius:3px;-moz-border-radius:3px;-webkit-border-radius:3px}p{margin:1em 0}a{color:#4183c4;text-decoration:none}body{background-color:#fff;padding:30px;margin:15px;font-size:14px;line-height:1.6}body>*:first-child{margin-top:0!important}body>*:last-child{margin-bottom:0!important}@media screen{body{box-shadow:0 0 0 1px #cacaca,0 0 0 4px #eee}}h1,h2,h3,h4,h5,h6{margin:20px 0 10px;padding:0;font-weight:bold;-webkit-font-smoothing:subpixel-antialiased;cursor:text}h1{font-size:28px;color:#000}h2{font-size:24px;border-bottom:1px solid #ccc;color:#000}h3{font-size:18px;color:#333}h4{font-size:16px;color:#333}h5{font-size:14px;color:#333}h6{color:#777;font-size:14px}p,blockquote,table,pre{margin:15px 0}ul{padding-left:30px}ol{padding-left:30px}ol li ul:first-of-type{margin-top:0}hr{background:transparent 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.s{color:#d14}.highlight .na{color:#008080}.highlight .nb{color:#0086b3}.highlight .nc{color:#458;font-weight:bold}.highlight .no{color:#008080}.highlight .ni{color:#800080}.highlight .ne,.highlight .nf{color:#900;font-weight:bold}.highlight .nn{color:#555}.highlight .nt{color:#000080}.highlight .nv{color:#008080}.highlight .ow{font-weight:bold}.highlight .w{color:#bbb}.highlight .mf,.highlight .mh,.highlight .mi,.highlight .mo{color:#099}.highlight .sb,.highlight .sc,.highlight .sd,.highlight .s2,.highlight .se,.highlight .sh,.highlight .si,.highlight .sx{color:#d14}.highlight .sr{color:#009926}.highlight .s1{color:#d14}.highlight .ss{color:#990073}.highlight .bp{color:#999}.highlight .vc,.highlight .vg,.highlight .vi{color:#008080}.highlight .il{color:#099}.highlight .gc{color:#999;background-color:#eaf2f5}.type-csharp .highlight .k,.type-csharp .highlight .kt{color:#00F}.type-csharp .highlight .nf{color:#000;font-weight:normal}.type-csharp .highlight .nc{color:#2b91af}.type-csharp .highlight .nn{color:#000}.type-csharp .highlight .s,.type-csharp .highlight .sc{color:#a31515}
+