Create walkthrough

[grosscol]

It was not readily apparent to outside observes what the heck is going on in the display lab's github repos. Since VRA is the repo that details the pipeline, it should have at least a simple walkthrough explaining what is going on in terms tractable to an interested external reader.

• text description of pipeline
• slides illustrating the operation as github.io ages under docs/ directory

[grosscol]

Initial stab at walkthrough text:
https://github.com/Display-Lab/vert-ramp-affirmation/blob/issue-13/walkthrough.md