Formatted all pages according to guidelines.

pages/common/virtualenv.md

@@ -1,16 +1,15 @@
 # virtualenv
 
-> Create virtual isolated Python environments
+> Create virtual isolated Python environments.
 
-- Create a new environment
+- Create a new environment:
 
 `virtualenv {{path/to/venv}}`
 
-- Start (select) the environment
+- Start (select) the environment:
 
 `source {{path/to/venv}}/bin/activate`
 
-- Stop the environment
+- Stop the environment:
 
 `deactivate`
-