move docs one level down to allow pydata deploy rynsc to be more selective
Large-ish docs refactor:

* most content under docs subdirectory
* fix all sphinx warnings
add local table of contents to FAQ
clean up thumbnail names
let build gallery work with unicode text in the plot
fix section underline lengths
add histogram example to gallery
add image_rgba example to gallery
add categorical demo to gallery
show quiver as well as streamline in gallery
add third row of thumbnails to index
change order of thumbs
split faq into general and techical questions
add full periodic table data, and periodic table example
add les mis example
fix bug in prev/next linking
add unemployment heat map example to gallery
typo'd commit ammend, commited more than intended
add new thumbs for index
fix text render