adding instructions to README for tracking thoughtbot/dotfiles repo

README.md

@@ -0,0 +1,19 @@
+thoughtbot dotfiles
+===================
+
+Install
+-------
+
+Clone this repository, change into the cloned directory, and run:
+
+    ./install.sh
+
+This will create symlinks for all config files in your home directory. You can
+safely run this file multiple times to update.
+
+Tracking thoughtbot
+-------------------
+
+    git remote add thoughtbot git@github.com:thoughtbot/dotfiles.git
+    git fetch thoughtbot
+    git checkout -b thoughtbot thoughtbot/master