Add example.config and main documentation of the roles_path feature.

examples/ansible.cfg

@@ -12,7 +12,6 @@
 
 hostfile       = /etc/ansible/hosts
 library        = /usr/share/ansible
-#roles_path    = /etc/ansible/roles
 remote_tmp     = $HOME/.ansible/tmp
 pattern        = *
 forks          = 5
@@ -23,6 +22,9 @@ sudo_user      = root
 transport      = smart
 remote_port    = 22
 
+# additional paths to search for roles in, colon seperated
+#roles_path    = /etc/ansible/roles
+
 # uncomment this to disable SSH key host checking
 #host_key_checking = False