fix: Move ISSUE_TEMPLATE/ under .github/

[simster7]

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this does not need to be in the release notes.
• The title of the PR is (a) conventional, (b) states what changed, and (c) suffixes the related issues number. E.g. "fix(controller): Updates such and such. Fixes #1234". Why? for the release notes.
• Optional. I've added My organization is added to the README.
• I've signed the CLA and required builds are green.