feat: add code fence

roles/jenkins/README.md

@@ -58,7 +58,7 @@ And include it in your playbook.
 
 Here is an example to get the list of plugins from an existing server:
 
-```
+```bash
 JENKINS_HOST=username:[email protected]:port
 curl -sSL "http://$JENKINS_HOST/pluginManager/api/xml?depth=1&xpath=/*/*/shortName|/*/*/version&wrapper=plugins" | perl -pe 's/.*?<shortName>([\w-]+).*?<version>([^<]+)()(<\/\w+>)+/\1 \2\n/g'|sed 's/ /:/'
 ```