How to include documentation in the automatically generated python wrapper?

[jwoillez]

At the moment, the ERFA documentation is in the *.c files, and therefore not available in a packaged version, the way most users will get it. I can see two options:

Option 1: Pull the sources with git and get the documentation from the *.c files, when generating the wrapper.

Option 2: Copy the documentation from the *.c to erfa.h when using erfa-fetch, and get it from erfa.h.

Opinions?

[jwoillez]

Note: Option 2 is liberfa/erfa#24