Support for embedding Maven coordinates into docs

[alanv]

We'd like to be able to associate class docs with Maven artifact coordinates as shown here at "belongs to Maven artifact".

For context -- the AndroidX project recently migrated to Dokka to generate docs. We previously used Doclava, which had a command-line argument for associating API surface with Maven coordinates. We were also using Doclava to generate a file representing the library's API surface, which meant it was a simple String -> API file mapping. Associating a library version with an API (for the "added in version" text seen here) worked similarly.

[martinbonnin]

@alanv Did you end up making this work? Looks like the androidx API reference now has the maven coordinates displayed?