Hello!

I'm trying to implement the version dropdown on erlang.org/doc and can't find any documentation for how the docs_config.js file should look and work? Also the release note where it was added mentions that its location can be configured, but that does not seem to be documented anywhere either?

I've dug through the code and have a basic understanding on how it works, but I think it would be good to add to the documentation in order to know which behaviour we can rely on.