ci: adds workflow for syncing docs out to docusaurus repo

[lukegalbraithrussell]

Summary

This adds a workflow that takes edits to the md docs in this repo and pushes it to the docusaurus build. This will be using a reusable workflow soon, and i'll replace this then.

Requirements

• 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.

[github-actions]

license-eye has checked 592 files.

Valid	Invalid	Ignored	Fixed
462	1	129	0

Click to see the invalid file list

• sync-docs-from-cli-repo.yml

Use this command to fix any missing license headers

```bash

docker run -it --rm -v $(pwd):/github/workspace apache/skywalking-eyes header fix

</details>

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 62.94%. Comparing base (f2a26f0) to head (5740366).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #29      +/-   ##
==========================================
+ Coverage   62.92%   62.94%   +0.01%     
==========================================
  Files         210      210              
  Lines       22127    22127              
==========================================
+ Hits        13924    13927       +3     
+ Misses       7117     7114       -3     
  Partials     1086     1086              

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[lukegalbraithrussell]

the if statement below means it only creates the PR on push and dispatch. but it'll run everything else as a test for PRs made

[zimeg]

Sweet PR for keeping all things up to date 📚 ✨

All of this looks good to me and the cases this runs for are solid too. I think this is good to merge but left one comment on the last step that is no blocker.

I look forward to the reusable workflow as well but am also so excited for a syncing workflow. It's neat stuff 🤖

[zimeg]

Suggested change

	- name: Output the pull request link
	if: ${{ steps.site-pr.outputs.pull-request-url }}
	run: |
	echo "Pull request created: ${{ steps.site-pr.outputs.pull-request-url }}" >> $GITHUB_STEP_SUMMARY

Quick note since this is useful to have, but IIRC this step was added for collecting links of various PRs made to multiple separate repos at a time - often for sample apps.

Here we target a single source of truth and this might not be as needed, but of course no need to change it! This is a note 👾