Issue Templates

@bsteubing I'd like to suggest we start using [issue templates](https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/configuring-issue-templates-for-your-repository) for our users to report issues. I think this can help us better manage AB development.

If you like this, I'll set up a draft and make it a PR so you can review.