"make docs" or such to build doxygen documentation #11949

Would be nice to have a "make docs" that builds the developer documentation. It is hosted on https://dev.visucore.com/bitcoin/doxygen/, but some users prefer an offline copy (and one up to date with their specific branch).

Essentially it would do:

doxygen doc/Doxyfile

(but taking into account build/source directories if separate)

It could also build other documentation in the future.

hey @laanwj , do you have an example of the expected result ?

You mean the doxygen output? Here's what the output looks like: https://dev.visucore.com/bitcoin/doxygen/

My pull request should do exactly that, make docs (after configuring the project) will generate the doxygen documentation in docs/doxygen/html.