Make sure that all plugins have nice auto-generated documentation in Sphinx

[mithro]

All the plugins should have nice documentation published on Sphinx.

[mithro]

@rw1nkler - What is the correct approach for this repo which is mostly C code? Something like the Verilog to Routing set up?

[mithro]

@tmichalak -- Who should take on this work?

[rw1nkler]

@rw1nkler - What is the correct approach for this repo which is mostly C code? Something like the Verilog to Routing set up?

A Sphinx setup for C/C++ code is simple. I can prepare it for this repository. The most important part is to document the code using Doxygen code comments.