[EOSIO/eos] Provide a basic Issue Template (#5321)

Must be placed within the default branch.

The text is displayed within every new issue, reminding the user to use other resources.

closes #5295
You can view, comment on, or merge this pull request online at:

https://github.com/EOSIO/eos/pull/5321

— Commit Summary —

* Provide a basic Issue Template

— File Changes —

A .github/issue_template.md (38)

— Patch Links —

https://github.com/EOSIO/eos/pull/5321.patch
https://github.com/EOSIO/eos/pull/5321.diff