[llvm] [Github] Add Pull Request template with links to Github docs/Discord/Forums (PR #71923)

[Tobias Hieta via llvm-commits]

https://github.com/tru approved this pull request.

I think this is fine, but I agree with @kbeyls that we should maybe include some of the more common questions we get like "how do I add reviewers" and "how often should I ping the issue"? These seems to be the most common questions we get.

https://github.com/llvm/llvm-project/pull/71923