Refactor the combine function to utilize a list.

This brings it inline with Bourbon.
Clean up some of the documentation
OCD cleanup
Add default styles around indicators and document

Also moved the internals for creating an indicator to a method
for easier sub class overrides.
Fix a missing back tick
Update the year on the license
Add a footer to the docs
Spruce up the front page
Add a Contributing.md file… just in case

https://github.com/blog/1184-contributing-guidelines
Remove the WIP and spruce up the main read me file