Design feedback for Handbook launch

Tracking design feedback here for @andrewmaier.

[x] The TOC columns should sort top to bottom, then left to right. They are currently sorting left to right: https://pages-internal.18f.gov/handbook/
[x] Tables overfloweth: https://pages-internal.18f.gov/handbook/professional-development-and-training/
[ ] Update template to use title
[ ] Remove lefthand padding from page Table of Contents
[ ] Add a CSS attribute for strong text in Markdown, ex **This should be bold**
[ ] Very minor, but you might want space around images
[ ] Very minor, missing styles for these contact cards

18F / hub