Merge pull request #10 from nmadhok/patch-1

Correct parameters spelling

README.rst

 
 .. code-block:: yaml
 
-    parametetrs:
+    parameters:
       iptables:
         service:
           enabled: True
 
 .. code-block:: yaml
 
-    parametetrs:
+    parameters:
       iptables:
         service:
           chain:
 
 .. code-block:: yaml
 
-    parametetrs:
+    parameters:
       iptables:
         service:
           chain: