Stub out prototype content

[tbaxter-18f]

We probably need to stub out the prototype content before we connect in the JS-driven bits and account for progressive enhancement.

This task is done when...

• [ ] Basic user flow through prototype is represented
• [ ] In the case JS does not load, users are presented with links to off-site content (to be replaced in JS-enabled situations).

[tbaxter-18f]

I believe this is the most-recent/correct copy: https://docs.google.com/document/d/1v2y9qm_KS_vPiAWLG5OB5AH66eXCY0f8ietumnVH8Oc/edit#heading=h.xtduyuslayo3

@durland18F can confirm

[durland18F]

Yes; the stuff that's in brackets (and sometimes green or red) is commentary.

(But you knew that!)