Code documentation and plugin for building

[mwmitchell]

Currently, Flux lacks documentation on its code/functions. Because of this, there's no way to build docs dynamically. Any public function/namespace within Flux should be documented with a doc string. Something like marginalia [1] could then be used for publishing docs.

1. https://github.com/gdeer81/marginalia

[mwmitchell]

Codox is another documentation system to checkout: https://github.com/weavejester/codox