Currently, we can put documentation in doc.md files, and even define groups inside them. I really like this way of documenting code without needing to add a huge documentation block at the start of a given header. See #21273.

I would like to add documentation to XFA without making the header grow to an unmanageable size. Putting a global doc.md into core/lib doesn't seem like a good fit to me. If there's some other component in core/lib someone wants to document more extensively, that would also need to go into the same doc.md there. Hence, I don't think the doc.md approach scales well here.

I think this could be solved by also allowing *.doc.md files, such as xfa.doc.md in core/lib.
This would be the necessary change in the doxyfile:

FILE_PATTERNS  = \
  doc.md \
  *.doc.md # <- here

Does anyone have thoughts on this?

ping @mguetschow