Hexdocs search engine for devs

[LostKobrakai]

@KristerV

For Linux and Windows there’s also Zeal, but I couldn’t get used to the interface. Also there’s only one broken repo that transforms hexdocs into docsets, which Zeal needs, so only Elixir itself is supported.

I was toying yesterday with porting the code to a ex_doc formatter (similar to the epub one), so they could be generated directly with ex_doc and possibly hosted by hexdocs.