Add checkboxes to issue template

[RayBB]

Is your proposal related to a problem?

The main thing I want to keep from those, is the checkboxes to make sure people have searched for their issue before. We have so many duplicates on all our repos, and it'll likely help.

Per: https://github.com/LemmyNet/lemmy-ui/pull/1211#pullrequestreview-1475594666

Describe the solution you'd like.

Add the checkboxes from here: https://github.com/LemmyNet/lemmy/blob/main/.github/ISSUE_TEMPLATE/BUG_REPORT.md

Docs: https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/syntax-for-githubs-form-schema#checkboxes

Describe alternatives you've considered.

n/a

Additional context

No response

[krestenlaust]

Agree. I wish github would show the search results to the title, when creating an issue, like stackoverflow does.