Improved documentation, esp. formatting
Added sphinx structure
Restructured readme.txt
Adjusted Sphinx configuration
More links.
Moved documentation to standard directory
readme: fixed enumeration
Ignore csv files & images generated by the script
Sphinx-based documentation.

For standard documentation generated from the readme and the module's
docstrings, run `make html` in the `docs` directory. Run `make` alone to get a
list of alternative formats (that are completely untested ...).