docs: LLM translation.

[AlliBalliBaba]

As mentioned in #2108, this PR adds a script to translate all English docs via Gemini. LLM translations are generally pretty good, I can't attest to the quality of these translations though as I don't speak any of the languages. wdyt?

[henderkes]

Does GitHub not show the changed workflow file? It just shows the massive list of docs instead.

[AlliBalliBaba]

No workflow yet as I'm not sure when it should run. Just ran the translations.php manually to see what translations would look like (all docs with gemini-flash takes about half an hour)

[henderkes]

Ah, I closed the docs folder and didn't see the file. Thanks, will take a look.

[henderkes]

We'll need to add integration with super linter so that AI can automatically fix what it breaks.

[henderkes]

Can we simply exclude the docs/<lang> folders from the linter? Perhaps that would be simpler.

Edit: probably a question for @dunglas

[AlliBalliBaba]

I added a translate.yaml workflow, not sure though how to actually test new workflows.

[henderkes]

As it's manually triggered, we can't trigger it before it's merged into the default branch (main) iirc.

  push:
    branches:
      - main
    paths:
      - 'docs/*'

Should be this though, so it's automatically opened after docs change.