Refresh a lot of the copy

This includes some small and some larger(er) changes, which I'll call out specifically in a moment, but generally:

* Typos and wording (small)
* Bring some tech stuff up to date (small)
* Change a few things about the rails engineering job description (bigger)
I think "just generally awesome" is a bit hyperbolic (says the guy who wrote a book with "Awesome" in the title :), so I tweaked it a bit with our "Bright, Goal-Oriented & Kind" phrase.  I could honestly lose this section, but it breaks the symmetry on the page