Update GitHub issue templates to redirect support requests to chat

.github/ISSUE_TEMPLATE/30-feature-request.md

@@ -0,0 +1,28 @@
+---
+name: ✨ Feature Request
+about: Request a feature or suggest other enhancements 💡
+---
+
+<!--
+   SUPPORT REQUESTS:
+   This is for requesting features in Mempool, not for support requests. 
+   If you have a support request, please join our Keybase or Matrix:
+   https://keybase.io/team/mempool
+   https://matrix.to/#/#mempool:bitcoin.kyoto
+-->
+
+### Description
+
+<!-- brief description of the feature request -->
+
+### Problem to be solved
+
+<!-- description of the the problem you're having -->
+
+### Proposed solution
+
+<!-- explain how you think we should solve the problem -->
+
+#### Additional info
+
+<!-- Additional information useful for implementing (e.g. docs, links, etc.) -->