Document permission differences with GitHub Actions #1673

Experimenting with Forgejo Actions this week, I've found several
differences with GitHub Actions in terms of token permissions and
access controls. This documents them in the "Known list of
differences".

Signed-off-by: Adam Williamson awilliam@redhat.com

Preview ready: https://forgejo.codeberg.page/@docs_pull_1673/

Note I did not cover forgejo/forgejo#10733 in this, because that seems clearly like a bug to me rather than intended (and thus documentable) behavior. But if that is not fixed, or if we only fix it on future releases, the true description would be:

"...The automatically-generated FORGEJO_TOKEN secret has full read/write permissions for all workflows except those triggered by the pull_request or pull_request_target events for a pull request from a forked repository. For that case, the token has read permissions only..."

Hmm, I don't see my change in the preview. Is the preview generation broken? I can't see how it would be possible for the changes to simply not appear at all.

When checking the preview, ensure that you change the "Docs" dropdown to "Next" -- eg. https://forgejo.codeberg.page/@docs_pull_1673/docs/next/user/actions/github-actions/