Use a monospaced font for snippet text.

*I* think it makes a nice distinction of content from UI, personally.
 We'll see what others think.

List of monospace fonts taken from
   http://www.w3schools.com/cssref/css_websafe_fonts.asp

Auditors: chris

Test Plan:
Manually view
   http://weekly-snippets.appspot.com/weekly?week=09-01-2014