ci: synchronize documentation pages on the tools.slack.dev site after changes

[lukegalbraithrussell]

Summary

This PR allows docs changes from this repo to be synced to the tools.slack.dev repo.

First, it syncs the changes and builds the entire docusaurus site with the changes.

If merged or workflow_dised, it then create a PR in the docs site repo

This should also work at a composite action in other repos methinks

Requirements (place an x in each [ ])

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.85%. Comparing base (79ad3a9) to head (38ecf51).
Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #423   +/-   ##
=======================================
  Coverage   99.85%   99.85%           
=======================================
  Files           7        7           
  Lines         702      702           
=======================================
  Hits          701      701           
  Misses          1        1           

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[zimeg]

@lukegalbraithrussell This is a super exciting change! 📚 ✨

I'm approving now and left a few comments with small changes, but nothing blocking IMO if this works as expected.

We might want to wait for #422 to land or merge this beforehand to test that in completeness? I do not know. The next note is interesting to me before all:

The matrix isn't necessary but this allows it to match the format of the reverse workflow, which will be easier for future adjustments

👾

I'd be so curious if setting up a composite action might make maintenance somewhat better overall?

From what I can tell, most of these steps will be the same across repos with a few different inputs, and I'm hoping we could maintain and share that workflow from one repo instead.

Now might be a nice time to set that up if it seems like it'd be useful, but I'm not wanting to slow down improvement elsewhere 🚀

[zimeg]

📝 The testing changes are super interesting but I'm leaving a comment that wonders if this should be left to the docs repo instead?

Otherwise this is exciting.