link to code implementation from website

It would be cool if we could link directly to the implementation of benchmarks and models from the website.
Since plugin structure follows `[vision | language] / [benchmarks | models] / `, all that is left is to find the `plugin directory`.
We could either query the library for this and look up the directory given an identifier, or store the directory in the database.

Start by tracing how the website identifies benchmark and model plugins, then inspect the library lookup and database paths described in the issue. Decide how the plugin directory is obtained for each identifier, and verify that website entries link to the corresponding implementation directory.

Written by the indexing model from the issue text.