[llvm] Update GitHub PR Greeter (PR #194307)

[Andrzej Warzyński via llvm-commits]

banach-space wrote:

> Nit: with the addition/restoration of the FAQ, the public email address policy is now mentioned twice (in the initial section and in the FAQ), even though it's arguably not the most important thing to emphasize early on in the review process.

It's a small change, so I've just fixed it (see this [commit](https://github.com/llvm/llvm-project/pull/194307/changes/f6f2d2c0ccca21b618dce0fae006b0d9427ac7fa))

> But my suggestion is to land this PR as-is instead of continued refinement and bikeshedding.

Agreed. Given that this PR has evolved a fair bit, I will give people one more day to review. 

Thank you all for you input!

https://github.com/llvm/llvm-project/pull/194307