add revision.source feature - link to page source instead of page history

[ntno]

Describe the problem you'd like to have solved

currently we have a revision.history feature. when enabled with the git revision plugin a link to the markdown's git history is added to the page.

i would like to insert a link to the markdown's git source code instead of its commit history (optional via a new feature flag)

Describe the ideal solution

when revision.source feature is enabled a link should be added to the revision partial:

See source code on <a href="https://github.com/ntno/mkdocs-terminal/blob/main/documentation/docs/configuration/plugins/git-revision.md">GitHub</a>.

this feature should work for all of the current options: GitHub, Bitbucket, Codeberg

Notes

• BitBucket currently points to the source code so we should consider what to do for this use case
• what are the accessibility implications of having two links both with the text "GitHub"? is this confusing? do we need to add a link title text