[llvm] [Docs] Update Maintainer in Developer Policy (PR #154687)

[Renato Golin via llvm-commits]

================
@@ -141,57 +141,79 @@ products.
 Maintainers are those volunteers; they are regular contributors who volunteer
 to take on additional community responsibilities beyond code contributions.
 Community members can find active and inactive maintainers for a project in the
-``Maintainers.rst`` file at the root directory of the individual project.
-
-Maintainers are volunteering to take on the following shared responsibilities
-within an area of a project:
-
-* ensure that commits receive high-quality review, either by the maintainer
-  or by someone else,
-* help to confirm and comment on issues,
-* mediate code review disagreements through collaboration with other
-  maintainers (and other reviewers) to come to a consensus on how best to
-  proceed with disputed changes,
-* actively engage with relevant RFCs,
-* aid release managers with backporting and other release-related
-  activities,
-* be a point of contact for contributors who need help (answering questions
-  on Discord/Discourse or holding office hours).
+``Maintainers.md`` file at the root directory of the individual project.
----------------
rengolin wrote:

Well, there are more `.md` files than `.rst` currently, so it's already "wrong". :smile: 

I changed one, then realized there were others. I'm happy to not change and continue "wrong" but unchanged for now and open a separate discussion later.

https://github.com/llvm/llvm-project/pull/154687