WIP: Bug 1038395 - Build CTA landing page for learners / makers

<http://localhost:9006/from/firefox-2014/>
<http://localhost:9006/for/learners/>
<http://localhost:9006/for/mentors/>
It's a bad/good habit of mine. I add "use strict" to all my js files, but @gvn pointed out to me that since we lint the crap out of our code before shipping, it's probably redundant. I'll take it out of `mad-libs.js`