Stage site on GH actions

[slawekjaranowski]

According to apache/maven-gh-actions-shared#40

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[Tibor17]

@slawekjaranowski
I understand site:stage but I want to ask you what benefit I should have.
It would be great to see the HTML web content in GH project and check or fix the Apt files if I see wrong headers or so. Would it be possible to do?

[slawekjaranowski]

@Tibor17
Content of target/stage is uploaded as GH artifact ... please look at action result for this PR, there is:
588-site-ubuntu-latest-18-ea-temurin

[Tibor17]

@slawekjaranowski
I understand that zipping the web content is the first try which requires some extra work to check it.
There is one more comfortable way with an example as follows.
We talked about it in the mailing list that there is Github support with gh-pages, example:

    # Push the book's HTML to github-pages
    - name: GitHub Pages action
      uses: peaceiris/actions-gh-pages@v3.6.1
      with:
        github_token: ${{ secrets.GITHUB_TOKEN }}
        publish_dir: ./_build/html

References:
https://jupyterbook.org/publish/gh-pages.html
https://stackoverflow.com/questions/8446218/how-to-see-an-html-page-on-github-as-a-normal-rendered-html-page-to-see-preview
Can you pls make a draft with GH pages?
I will appove this PR.

[slawekjaranowski]

GITHUB_TOKEN for PR build from fork has read-only access so will be not possible to store something in repo.

Additionally we should manage many pages for master and each PR in separate space, cleanup outdated etc ... it is too complicated.

I hope that current solution is good enough.