Added a new simple theme with simple and visible code formatting. Useful for programmers and people who are not going to use these for HTML export or printing.
Changed default github theme to be more readable with Frutiger font, changed the italics for a more eye-catching red-border and grey background, and changed the code to be Source Code Pro. Increased font size and overall just made it a bit more enjoyable to read.
Changed fonts to sans-serif all over the board, instead of having a senseless “Georgia” and `serif` after “Frutiger” as the default font. Sans-serif definitely reads better in this font!
Changed filename from github.css to jslvtr.css
Merge pull request #5 from jslvtr/master

Added a new simple theme with simple and visible code formatting, and changed github.css theme to a different, more readable theme.