Provide Zeal/Dash docsets for all packages

[Leonidas-from-XIV]

This one is a bit of a pie-in-the-sky idea but I recently read the post How I’m a Productive Programmer With a Memory of a Fruit Fly and in it it mentions Zeal/Dash which are offline documentation browsers for multiple programming languages.

There is an existing docset for OCaml (although stuck at version 4.07) but given OCaml.org V3 is generating documentation for the packages in OPAM it would be nice to also generate corresponding docsets.

This way people coming to OCaml could continue using their tools and not need to switch to OCaml-specific tools like ocp-browser.

[cuihtlauac]

stalled: when odoc will generate dash doc, ocaml.org should tell about it and explain where to get it, how to use it