Added a basic install doc.

docs/install.rst

@@ -0,0 +1,20 @@
+Installation
+=============
+
+Installing RTD is pretty simple. Here is a step by step plan on how to do it.
+
+    virtualenv rtd
+    cd rtd
+    . bin/activate
+    mkdir checkouts
+    cd checkouts
+    git clone http://github.com/beetletweezers/tweezers.git
+    cd tweezers
+    pip install -r pip_requirements.txt
+    #Have a beer
+    ./manage.py syncdb
+    #Make sure you create a user here
+    ./manage.py migrate
+    ./manage.py update_repos
+    #Have another beer
+    ./manage.py runserver