Add Examples and Documentation

[akimbler]

See Title

[tsalo]

How do you want to set this up? I think examples are relatively limited, so they could probably just go in the README, but if we want to be extensive in our documentation we could set things up to build with Sphinx and have an RTD site.

Also, do we want to centralize documentation of cis-bidsify, cis-processing, and cis-xget under cis-processing (either in the README, RTD, or the wiki)?

[akimbler]

I think having an example run in the README works perfectly fine for the individual cis-xget and cis-bidsify repos. Working on centralizing them under cis-processing seems like the best option for now, I agree. I just want some barebones documentation on each repo just for use cases where the user isn't wanting to work with cis-processing in its entirety