Publish from GitHub Actions (#30288)

* Publish from GitHub Actions

* Break out instructions into release train issue template

scripts/create-release-issue.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+VERSION=$1
+if [ -z $VERSION ]
+then
+  echo specify the version name to be released, eg. 1.0.0
+else
+  sed -e 's/\$VERSION\$/'$VERSION'/g' scripts/release-train-issue-template$2.md > /tmp/release-$VERSION.md
+  echo Created $(hub issue create -F /tmp/release-$VERSION.md --browse)
+fi

scripts/release-train-issue-template.md

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+Release Akka $VERSION$
+
+### Before the release
+
+- [ ] Make sure all important / big PRs have been merged by now
+- [ ] Create a news item draft PR on [akka.github.com](https://github.com/akka/akka.github.com), using the milestone
+- [ ] Make sure to update `versions.json` in it
+
+### Cutting the release
+
+- [ ] Make sure any running [actions](https://github.com/akka/akka/actions) for the commit you would like to release have completed.
+- [ ] Tag the release `git tag -a -s -m 'Release v$VERSION$' v$VERSION$` and push the tag `git push --tags`
+- [ ] Check that the GitHub Actions release build has executed successfully (it should publish artifacts to Sonatype and documentation to Gustav)
+
+### Check availability
+
+- [ ] Check [reference](https://doc.akka.io/docs/akka/$VERSION$/) documentation
+- [ ] Check the release on [Maven central](https://repo1.maven.org/maven2/com/typesafe/akka/akka-actor_2.13/$VERSION$/)
+
+### When everything is on maven central
+
+- [ ] `ssh akkarepo@gustav.akka.io`
+  - [ ] update the `current` links on `repo.akka.io` to point to the latest version with
+       ```
+       ln -nsf $VERSION$ www/docs/akka/current
+       ln -nsf $VERSION$ www/api/akka/current
+       ln -nsf $VERSION$ www/japi/akka/current
+       ```
+  - [ ] check changes and commit the new version to the local git repository
+       ```
+       cd ~/www
+       git add docs/akka/current docs/akka/$VERSION$
+       git add api/akka/current api/akka/$VERSION$
+       git add japi/akka/current japi/akka/$VERSION$
+       git commit -m "Akka $VERSION$"
+       ```
+  - [ ] push changes to the [remote git repository](https://github.com/akka/doc.akka.io)
+       ```
+       cd ~/www
+       git push origin master
+       ```
+
+### Announcements
+
+- [ ] Merge draft news item for [akka.io](https://github.com/akka/akka.github.com)
+- [ ] Create a [GitHub release](https://github.com/akka/akka/releases) with the next tag version `v$VERSION$`, title and a link to the announcement
+- [ ] Send a release notification to [Lightbend discuss](https://discuss.akka.io)
+- [ ] Tweet using the akkateam account (or ask someone to) about the new release
+- [ ] Announce on [Gitter akka/akka](https://gitter.im/akka/akka)
+- [ ] Announce internally