[tutorial v1.1_011] Or a sub family

Inside a family, we can have variables or families.

The "type" for family "manual" became unecessary because container an other family, so it's not a variable.
The description can now be has family comment.

In disabled attribute, it's better tu use relative path (we will see the reason in an other slide).

firefox/10-manual.yml

@@ -2,7 +2,9 @@
 ---
 version: 1.1
 
-manual:
-  description: Manual proxy configuration
+manual:  # Manual proxy configuration
+
+  http_proxy:
+    description: HTTP Proxy
     type: family
 ...