Document infra internal-facing announcements

Author: jieyouxu

src/SUMMARY.md

@@ -118,6 +118,7 @@
         - [rust-bots server](./infra/docs/rust-bots.md)
         - [rust-lang/rust CI](./infra/docs/rustc-ci.md)
         - [Sentry](./infra/docs/sentry.md)
+        - [Internal-facing infrastructure announcements](./infra/docs/internal-announcements.md)
 - [Language](./lang/index.md)
     - [RFC Merge Procedure](./lang/rfc-merge-procedure.md)
     - [Triage Meeting Procedure](./lang/triage-meeting-procedure.md)

src/infra/docs/dev-desktop.md

@@ -214,6 +214,12 @@ suggestions, get in touch with the [infrastructure team]:
 
 We might ask you to create an issue in the [rust-lang/simpleinfra] repository.
 
+## Announcements of Dev Desktop changes
+
+The Infrastructure Team will announce significant Dev Desktop changes through the
+[`#t-infra/announcements`] Zulip channel.
+
+
 [cloud compute program]: https://foundation.rust-lang.org/news/2021-11-16-news-announcing-cloud-compute-initiative/
 [[email protected]]: mailto:[email protected]
 [infrastructure team]: https://www.rust-lang.org/governance/teams/infra
@@ -225,3 +231,5 @@ We might ask you to create an issue in the [rust-lang/simpleinfra] repository.
 [visual studio code]: https://code.visualstudio.com/
 [certain teams]: https://github.com/search?q=repo%3Arust-lang%2Fteam+path%3Ateams%2F*.toml+dev-desktop&type=code&ref=advsearch
 [simpleinfra-vars-user-config]: https://github.com/rust-lang/simpleinfra/blob/dbf839ef25155df1f33c18f151283436b0f70f3b/ansible/roles/dev-desktop/defaults/main.yml#L12:L16
+[`#t-infra/announcements`]:
+    https://rust-lang.zulipchat.com/#narrow/channel/533458-t-infra.2Fannouncements

src/infra/docs/internal-announcements.md

@@ -0,0 +1,13 @@
+# Internal-facing infrastructure announcements
+
+For significant _internal facing_ infrastructure changes or updates, the Infrastructure Team can
+announce that change in the infrastructure announcement Zulip channel [`#t-infra/announcements`].
+Please keep in mind that we would like to keep that channel to be _low traffic_ and have a _high
+signal-to-noise ratio_.
+
+By _internal facing_, we mean infrastructure that primarily is used by or only impacts project team
+members and other specific project-internal users (such as [Dev Desktop](./dev-desktop.md) users).
+
+
+[`#t-infra/announcements`]:
+    https://rust-lang.zulipchat.com/#narrow/channel/533458-t-infra.2Fannouncements