chore: contribution guidelines about paid features (#11653)

* chore: contribution guidelines about paid features

* Update CONTRIBUTING.md

Co-authored-by: Neil Kakkar <neilkakkar@gmail.com>

Co-authored-by: Neil Kakkar <neilkakkar@gmail.com>

CONTRIBUTING.md

@@ -14,6 +14,10 @@ Spotted a bug? Has deployment gone wrong? Do you have user feedback? Raise an is
 
 ... or pick up and fix an issue if you want to do a Pull Request.
 
+## Issues with paid features
+
+We prefer not to accept external contributions for paid features. If you don't see the feature on your local build, it's most probably paid.
+
 # Feature requests
 
 Raise an issue for these and tag it as an Enhancement. We love every idea. Please give us as much context on the why as possible.