Allow searching for modules

[Crote]

Modules are currently very hard to discover. Let's say I want to find the functions contained in the module 'List'. There is currently no way to do this: the only way to find it is to guess the right package on elm package search and find it from there.

I'd instead like to be able to search on "List", and have an entry returned linking to http://package.elm-lang.org/packages/elm-lang/core/5.0.0/List. Furthermore, as a submodule List.Extra exists in elm-community/list-extra, an entry for that should be returned as well.

[klaftertief]

There is an undocumented feature for something similar, but it's a little bit too strict at the moment. One can prefix a search query with module: to search for all functions in the given module, e.g. module:List to show all functions in a List module. It is too strict that it does not find List.Extra functions.

The feature is undocumented as it needs better UI (some search switch, not a keyword prefix) and not really fleshed out.
A section header with some module info and documentation should be put above the module contents, and those should maybe be collapsed per default.

Thanks for the suggestion.