Add better documentation throughout the Module

[stadelmanma]

It would be good to implement something using read the docs and an automatic documentation builder like sphinx. OpenPNM likely has a lot of the logic I would need to implement already figured out. Also sphinx has examples and links to projects who use their system.

I would want to go through and throughly document each function's parameters, purpose and provide an example. I figure there is a PEP standard or something I can use as a guideline to enforce consistency.

Ideally I could incorporate my current examples as well somehow.

[stadelmanma]

I'll upload this to a read the docs site eventually.