Pass config and theme options

[dignifiedquire]

I'm trying to setup a gulp task which uses the documentation.yml from the root of the project and a custom theme, but I can't find a place to pass this option through. It seems these options are not exposed in https://github.com/documentationjs/documentation/blob/master/index.js or am I missing something?

[tmcw]

Right now it's not possible to pass a configuration file through gulp-documentation: config loading is done in sharedInputOptions, which is part of the documentation bin, and not exposed in the public API. Given that gulp-documentation and there'll be other kinds of access, maybe we should take an approach like .babelrc and parse it by default, even sometimes when it's not what you asked for :)

Or we could just expose a path to loadConfig in the Node API path?