Add a sample doc in markdown format.

BUG=skia:
R=epoger@google.com, halcanary@google.com, borenet@google.com, jcgregorio@google.com, bungeman@google.com

Author: mtklein@google.com

Review URL: https://codereview.chromium.org/146943002

git-svn-id: http://skia.googlecode.com/svn/trunk@13175 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed