[DOC] update usage.md

docs/usage.md

@@ -197,7 +197,6 @@ Alignment will be performed on the `mm10` genome with default paramters.
 Multi-hits will not be considered and duplicates will be removed.
 Note that by default, no filters are applied on DNA and restriction fragment sizes.
 
-
 ```bash
 nextflow run main.nf --input './*_R{1,2}.fastq.gz' --genome 'mm10' --digestion 'dnpii'
 ```
@@ -209,7 +208,7 @@ Alignment will be performed on the `mm10` genome with default paramters.
 Multi-hits will not be considered and duplicates will be removed.
 Contacts involving fragments separated by less than 1000bp will be discarded.
 
-```
+```bash
 nextflow run main.nf --input './*_R{1,2}.fastq.gz' --genome 'mm10' --dnase --min_cis 1000
 ```