Writing chapter 4. includes:

- reasons to use bootstrap
- basic bootstrap
- starts on slightly more advanced bootstrap for Articles.all.
Pausing for the night.

- buttons!
- next up: tables.
Fixes #10
Updated Chapter 4, created a stub and roadmap for Chapter 5.
Adds in more code highlighting. YAY.
Merge pull request #13 from ClevelandOnRails/chapter4

Chapter 4