[llvm] [Docs] Instructions for new contributors to find reviewers (PR #71936)

[Pablo Antonio Martinez via llvm-commits]

pabloantoniom wrote:

> LGTM, thank you!
> 
> I guess you may want me to merge this PR for you as you may not yet have merge rights?

Yes please! I don't see any merge button, so I guess I don't have merge rights

https://github.com/llvm/llvm-project/pull/71936