Add documentation.

Change-Id: I8197ec2e52596fa4136f8af9aa93ea06e56d4d0d
diff --git a/.gitignore b/.gitignore
index 2890290..d301ce7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,6 @@
 MANIFEST
 .tox
 *.pyc
+doc/build
+doc/source/sourcecode
+*~