🚨 Fix linting error in README

Author: jemrobinson

README.md

@@ -135,7 +135,7 @@ This allows a user to make a request for "all primary user groups needed by memb
 
 which will return:
 
-```
+```ldif
 dn:CN=Detectives,OU=groups,DC=<your domain>
 objectClass: groupOfNames
 objectClass: posixGroup