Move all feedback to community forum (#5923)

The feedback tickets on github is an extra entry point for us to filter
through and triage. I propose we update the template and funnel all
feedback to community for our team to bring forward instead. This way
our users will have our full attention and will not feel like we have
not actioned on any of the feedback.


## Test plan
N/A
<!-- Required. See
https://docs-legacy.sourcegraph.com/dev/background-information/testing_principles.
-->

## Changelog

<!-- OPTIONAL; info at
https://www.notion.so/sourcegraph/Writing-a-changelog-entry-dd997f411d524caabf0d8d38a24a878c
-->

.github/ISSUE_TEMPLATE/feedback.md

@@ -0,0 +1,12 @@
+---
+name: '❌ Do not submit feedback or feature requests here'
+about: 'We are *not* accepting feedback or feature requests through GitHub issues, instead please submit feedback directly to the Community Forum.'
+title: ''
+labels: 'customer-feedback'
+assignees: ''
+
+---
+
+# We do not accept feedback or feature requests on GitHub
+
+Instead, please post your requests to the [Community Forum](https://community.sourcegraph.com/new-topic?title=&body=&category=cody&tags=feedback,vs-code).