Add select-mode, version, pack and publish sub-actions (#656)

* Add select-mode, version, and publish sub-actions

* Rename

* No github-token needed for select-mode for now

* extend select-mode with publish-plan check and upload

* Rename base-branch to pr-base-branch

* add `pack` subaction

* `--from-pack` support in the publish subaction

* rename CLI arg

* update rolldown config

* rename pack dir input/output

* tweak retendion days

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Co-authored-by: Mateusz Burzyński <mateuszburzynski@gmail.com>

publish/README.md

@@ -0,0 +1,3 @@
+# changesets/action/publish
+
+TODO