Improve documentation of molecule init role (#3393)

Author: ssbarnea

docs/getting-started.rst

@@ -32,7 +32,7 @@ To generate a new role with Molecule, simply run:
 
 .. code-block:: bash
 
-    $ molecule init role my_new_role --driver-name docker
+    $ molecule init role acme.my_new_role --driver-name docker
 
 You should then see a ``my_new_role`` folder in your current directory.
 

src/molecule/command/init/role.py

@@ -37,9 +37,9 @@ class Role(base.Base):
     """
     Init Role Command Class.
 
-    .. program:: molecule init role foo
+    .. program:: molecule init role acme.foo
 
-    .. option:: molecule init role foo
+    .. option:: molecule init role acme.foo
 
         Initialize a new role.