Expose Internal Modules

[emekoi]

Would it be possible to expose the modules:

• Text.MMark.Render
• Text.MMark.Trans
• Text.MMark.Type

I want to implement custom rendering logic, generating different header ids than what mmark does as well as header anchors. While this is currently possible using blockRender and discarding the old rendering function, that isn't really compositional and relies on manually inserting a "reset" pass to replace the default render function. Furthermore, exposing these modules allows users to write monadic rendering passes if they need them.