Convert to markdown/html

This pull requests converts the source code policy from raw text to markdown so that it can be displayed as HTML. Specifically:

1. Convert all numbered lists to decimal-based lists
2. Create a lightweight layout which:
  1. Includes the CFPB stylesheet and fonts
  2. Adds a few lines of CSS to preserve numbering and formatting with the original

## Before

![before](https://cloud.githubusercontent.com/assets/282759/3042232/d8c95500-e0fb-11e3-9235-38ed55df8743.png)

## After

![after](https://cloud.githubusercontent.com/assets/282759/3042197/8a14f2d4-e0fb-11e3-8a21-23198dc2ef85.png)

## Rendered

http://ben.balter.com/source-code-policy/

## Source on GitHub

https://github.com/benbalter/source-code-policy/blob/gh-pages/cfpb-source-code-policy.md

## Two notes

1. because the `gh-pages` branch did not exist upstream, this pull request is to master, but once merged, a `gh-pages` branch is required to publish.

2. It may make sense to submodule this repository into `cfpb.github.io` where layouts could be more easily shared, but the content could remain separate.

Fixes https://github.com/cfpb/source-code-policy/issues/2.