Highlight trailing '.' in command so it wont be missed.

Author: tomchristie

docs/tutorial/quickstart.md

@@ -19,7 +19,7 @@ Create a new Django project named `tutorial`, then start a new app called `quick
     pip install djangorestframework
 
     # Set up a new project with a single application
-    django-admin.py startproject tutorial .
+    django-admin.py startproject tutorial .  # Note the trailing '.' character
     cd tutorial
     django-admin.py startapp quickstart
     cd ..