configure where documentations files are

[jckr]

current situation

Today even though we expose the location of documentation files in the configuration, ocular-gatsby expects them to be in a /docs folder. That '/docs' path is somewhat magical in the ocular-gatbsy universe, this is where the ToC will be found, this is also the relative path of the first documentation page in the generated web site.

goal

we should be able to expose where markdown files are.
this is also linked to #144 - the website could be generated somewhere else than at /docs

[javidhsueh]

@jckr should we close this issue now?