Example Generate documentation from doc strings

[manuGil]

This is an example of how to use autodoc to generate documentation from doc string for Sphinx.
Once the the PRs with doc strings are merged, we can use this as an example to add more models to the models.rst file.

The content of models.rst most be in reStructured text (Marckdown won't be always be rendered properly)
If necessary, other parts of the source code can be documented in different RST files.