Please include release date information in version info

[bondolo]

When I go to the docs.rs page for a crate it can be difficult to figure out when the versions of the crate were released. It would also be useful to know when a version was yanked (and possibly a link to the reason).

[syphar]

• we already have the release date in our database
• yank reason is more tricky, we don't have that yet, and I'm not even sure if it's in the git index files somewhere, or we would have to fetch it via API.

I could see this as a simple tooltip over the version number, or in the list itself if there's enough space.

I would totally review & accept a PR for this :)

[GuillaumeGomez]

I opened #2847.