Updating README to show people how to change their default shell.

README.textile

@@ -8,9 +8,15 @@ h2. Setup
 
   @git clone git://github.com/robbyrussell/oh-my-zsh.git@
 
-2. Symlink the zsh config with: @ln -s ~/oh-my-zsh/zshrc ~/.zshrc@
+2. Symlink the zsh config with:
 
-3. Start / restart zsh (open a new terminal is easy enough..)
+  @ln -s ~/oh-my-zsh/zshrc ~/.zshrc@
+
+3. Set zsh as your default shell:
+
+  @chsh -s /bin/zsh@
+
+4. Start / restart zsh (open a new terminal is easy enough..)
 
 h3. Problems?