Core documentation cleanup

[wikimatze]

After two tries this is the final one - it just cleaned up the documentation.

[ujifgc]

Looks fine to me.

[namusyaka]

Great 👍
By the way, are module and class name comment not needed?
like this end # Padrino

[ujifgc]

Ideally, end # Padrino spews are not needed because the code is well structured and methods are short.