typo corrections

doc/pipeline_building_cec.md

@@ -339,7 +339,7 @@ cd ..
 
 ## Run nextflow
 
-It is better to writ a script as a.sh file to lauch nextflow : Here is the RNAseq_script for Kallisto:
+It is better to write a script as a.sh file to lauch nextflow : Here is the RNAseq_script for RNAseq_cec pipeline with both kallisto and bowtie2:
 ```sh
 ./nextflow run src/RNAseq_cec.nf \
         -profile psmn \