Tidy up comments, add some docs/examples.

README.rst

 
 ``Configuration``
 =================
-Every option available in the templates can be set in pillar. Settings under 'salt' will be overridden by more specific settings under ``salt['master']``, ``salt['minion']`` or ``salt['cloud']``
+Every option available in the templates can be set in pillar. Settings under 'salt' will be overridden by more specific settings under ``salt['master']``, ``salt['minion']`` or ``salt['cloud']``. Options specified in ``salt['minion']`` which are not present in the default configuration file will be added to the end of the configuration file.
 
 ::
 

pillar.example

     mine_functions:
       network.interface_ip: [eth0]
 
+    # other 'non-default' config
+    auth_keytab: /root/auth.keytab
+    auth_principal: kadmin/admin
+
   # salt cloud config
   cloud:
     master: salt

salt/files/minion.d/f_defaults.conf

 {% endif %}
 {%- endif %}
 
-############  Other settings  ############
-##########################################
 {%- for configname in cfg_minion %}
 {%- if configname not in reserved_keys and configname not in default_keys %}
 {{ configname }}: {{ cfg_minion[configname]|json }}