Features page: link dependent features

[llogiq]

Currently, the features page is already quite helpful for finding out about what dependencies' features a feature will activate, but it would be even more useful to make that depended-on features link to their respective entries in that crate's features page on docs.rs.

[syphar]

thank you for that idea!

my first hunch is that this is definitely possible.

It would involve:

• parsing the feature definition properly (things like optional dependencies krate?/feature syntax
• adding HTML anchors to the feature names in the view
• using the stored dependencies so we know the semver of the dependences
• generate a link to the correct anchor on that feature page, for the right semver of that dependency.