Support for rendering various documentation formats

[bkabrda]

Hi, I'd like to be able to generate markdown in addition to html with griffin. There are 2 ways I see this could be done (and both could actually bring some benefit):

• griffin could accept -f/--output-format argument that would determine which builtin template to use. IMHO this should be fairly easy to implement, we could just tell jinja to render this directory instead of that, jinja doesn't really care if it's rendering html or markdown.
• Additionally, it might make sense to allow users to provide their own custom templates (-t/--template or so, could be mutually exclusive with -f) if they wanted to change the way the generated html/markdown/whatever looks or provide template for another format. This would also require well documenting the "API" for the jinja context variables, IOW what the variables are called and what exactly they contain - once we allow this feature, every change in jinja context variables could mean regression from user POV.

Any one of these features would solve my use case and I think they could both coexist and be useful - so let's discuss here and open a new issue for the feature(s) that seem ok to you.
Thanks for considering!