Add issue and PR templates

[alexeagle]

This helps a lot to make initial user interactions at a higher quality, so maintainers don't spend as much time asking for clarifications and so on.

See https://docs.github.com/en/github/building-a-strong-community/configuring-issue-templates-for-your-repository

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: alexeagle
To complete the pull request process, please assign after the PR has been reviewed.
You can assign the PR to them by writing /assign in a comment when ready.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[gravypod]

We may want to do some edits in the future. I'm not a huge fan of the

...

tags being used when we can just use codeblocks. This is still a step in the right direction though and we can always work from here as a base.