Update website-label-community-contributions.yml message.

Since the email I received specifically pointed out to me that I could help improve the message within, I went ahead and updated it.

The updates are only grammatical.

"come back to you" usually means physically returning to someone. "get back to you" usually means a kind of response. get back to you come back to you Google search

I don't think its usual to "mention someone something". There is a similar difference between "tell" and "say". So I just replaced it with "ask".

None of these are huge deals. Just trying to help. :)