chore: add feature requests to contributing.md (#2542)

.github/contributing.md

@@ -11,6 +11,7 @@ Thank you for contributing to Rafiki :tada: Your contributions are essential to
 
 - [Types of contributions](#types-of-contributions)
   - [:mega: Discussions](#mega-discussions)
+  - [:rocket: Feature Requests](#rocket-feature-requests)
   - [:beetle: Issues](#beetle-issues)
   - [:hammer_and_wrench: Pull requests](#hammer_and_wrench-pull-requests)
 - [Working in the rafiki repository](#working-in-the-rafiki-repository)
@@ -35,6 +36,9 @@ Discussions are where we have conversations about Rafiki.
 
 If you would like to discuss topics about the broader ecosystem, have a new idea, or want to show off your work - join us in [discussions](https://github.com/interledger/rafiki/discussions).
 
+### :rocket: Feature Requests
+We use GitHub issues to track feature requests. If there is something that you would like to see implemented in Rafiki, open an issue using the "Feature or Feature Subtask" template. Please make sure you check whether the feature has already been requested by searching existing open issues first before opening a new one. 
+
 ### :beetle: Issues
 
 We use GitHub issues to track tasks that contributors can help with. We haven't finalized labels yet for contributors to tackle. If you want to help with work related to an issue, please comment on the issue before starting work on it.