Modify GH Issues (All Feedback Welcome)

[abejgonzalez]

Related issue:

Type of change: new feature

Impact: other

Release Notes
This PR cleans up the GH issues to use the new issues template feature of GH and redirects questions/support to the mailing list / other forums (hopefully to move some question traffic there and just have GH serve as a features/bug tracker). An example of this working is here https://github.com/abejgonzalez/chipyard/issues when you open a new issue.

GH Issues Template Feature: https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/configuring-issue-templates-for-your-repository

Changes

• Only support bug reports and feature requests (deletes the other and questions issue templates)
  • The issue templates now have checkboxes requiring people to read the docs / search things before submitting
  • Also, has other required boxes to fill out
• Show the mailing list / RC / Chisel support links right before creating an issue

[tymcauley]

This looks like an awesome feature! Thanks for implementing this.

[jerryz123]

Very cool.