Improve formatting of the README

README.adoc

@@ -242,7 +242,9 @@ impl Widget for Win {
 NOTE: The `struct Win` is now automatically created by the attribute, as are the function `root()` and the associated types `Model`, `ModelParam`, `Msg` and `Container`.
 You can still provide the method and the associated types if needed, but you cannot create the `struct`.
 
-NOTE: To benefit from better error messages, enable the following features:
+[NOTE]
+====
+To benefit from better error messages, enable the following features:
 
  * relm/unstable
  * relm-attributes/unstable
@@ -255,6 +257,7 @@ To do so, add the following lines to your `Cargo.toml`:
 [features]
 default = ["relm/unstable", "relm-attributes/unstable", "relm-derive/unstable"]
 ----
+====
 
 [NOTE]
 ====