feat(docs): allow reference to a particular commit or tag

[wei3erHase]

Component

Forge

Describe the feature you would like

When running forge doc, there's a reference to the git source in the mdbook, that aims to the latest (current) commit from which the docs are generated. On normal development process, dev and main branches should be locked and accessible through PRs, that may be squashed and merged into, so the "latest commit" from which the docs are generated ends up being inexistent.

• Add a way of specifying a commit hash or a github tag to the "source code"

Additional context

No response

[lnist]

It would be beneficial to be able to give the entire prefix http url. We currently generate docs from a different repository than the one with the solidity files (by referencing an npm package with the files), and this generates urls to the wrong repository also.