Comment changeset status in PRs (#625)

* Initial implementation

* Fix

* fix

* fix

* Make it look nicer

* Update docs

* Rename to pr-status-comment

* Remove outputs

* Update path

* update name

* Checkout PR in a detached worktree (#626)

Co-authored-by: bluwy <bjornlu.dev@gmail.com>

* Move comment to separate job

* Loosen event requirement

* Update

* Apply suggestions from code review

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

* Use TLA

* use using

* Remove test log

---------

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

README.md

@@ -2,6 +2,10 @@
 
 This action for [Changesets](https://github.com/changesets/changesets) creates a pull request with all of the package versions updated and changelogs updated and when there are new changesets on [your configured `baseBranch`](https://github.com/changesets/changesets/blob/main/docs/config-file-options.md#basebranch-git-branch-name), the PR will be updated. When you're ready, you can merge the pull request and you can either publish the packages to npm manually or setup the action to do it for you.
 
+There are also sub-actions hosted in this repository. Check out their respective READMEs for more details:
+
+- [pr-status](./pr-status/README.md): Generate changeset status in PRs.
+
 ## Usage
 
 ### Inputs