Add question template

[triallax]

Checklist

• I checked, but didn't find any duplicates (open OR closed) of this issue in the repo.
• I have read the contribution guidelines given at https://github.com/TeamNewPipe/NewPipe/blob/HEAD/.github/CONTRIBUTING.md.
• This issue contains only one feature request. I will open one issue for every feature I want to request.

Describe the feature you want

Add an issue template for questions. This was hinted at in #5298; the problem with GitHub Discussions though is that they're not currently supported in the GitHub API, so no third-party clients support them.

How will you/everyone benefit from this feature?

People will be able to ask questions on GitHub instead of having to join the IRC room if they don't want to. Also, these questions won't be lost to time as in IRC.