Add generated pygments stylesheet.

- Link to pygments.css in layout template.
Use custom style based off of github styling.

- Pulled from https://github.com/hugomaiavieira/pygments-style-github.
Set specific styling on highlight class.
Move content element definition to layout template.

- Markdown files won't need to define the content div.
- Remove content div from index and about HTML pages.
Define styling for posts.

- Reset padding and margins on HTML header tags to 0.
- Add specific styling for h1, h2, and h3 tags.
Add Rakefile for common tasks.

- Add deploy config setting to YAML file.
- Create Rakefile with tasks to build blog and deploy remotely.
- Update readme with explanation of Rakefile and the uses of it.