[llvm] [Docs] [Developer Policy] Document best practice of not tagging a username in commit messages and PR descriptions (PR #164328)

[David Justo via llvm-commits]

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@@ -413,6 +413,10 @@ Below are some guidelines about the format of the message itself:
   message self-explanatory. Note that such non-public links should not be
   included in the submitted code.
 
+* Avoid 'tagging' someone's username in your commits and PR descriptions
+  (e.g. `@<someUser>`), doing so results in that account receiving an email
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davidmrdavid wrote:

good point, replaced here: https://github.com/llvm/llvm-project/pull/164328/commits/9a42646facd868f746f04055643fa2b8f2096468

thanks!

https://github.com/llvm/llvm-project/pull/164328