release steps: announce on Reddit

Author: SethTisue

Diff for: .github/ISSUE_TEMPLATE/release.md

@@ -174,6 +174,7 @@ If there are delays downstream, at some point it may make sense to go ahead and
 - [ ] Unblock the release in Scala Steward by PRing an update to [default.scala-steward.conf](https://github.com/scala-steward-org/scala-steward/blob/master/modules/core/src/main/resources/default.scala-steward.conf)
 - [ ] Ensure SDKMAN makes the release available (see scala/scala-dev#782)
 - [ ] ask Seth to announce on #scala IRC
+- [ ] Announce on https://reddit.com/r/scala
 
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