docs($rootScope): rearrange event listener docs

src/ng/rootScope.js

@@ -627,10 +627,6 @@ function $RootScopeProvider(){
        * Listens on events of a given type. See {@link ng.$rootScope.Scope#$emit $emit} for discussion of
        * event life cycle.
        *
-       * @param {string} name Event name to listen on.
-       * @param {function(event, args...)} listener Function to call when the event is emitted.
-       * @returns {function()} Returns a deregistration function for this listener.
-       *
        * The event listener function format is: `function(event, args...)`. The `event` object
        * passed into the listener has the following attributes:
        *
@@ -641,6 +637,10 @@ function $RootScopeProvider(){
        *     propagation (available only for events that were `$emit`-ed).
        *   - `preventDefault` - `{function}`: calling `preventDefault` sets `defaultPrevented` flag to true.
        *   - `defaultPrevented` - `{boolean}`: true if `preventDefault` was called.
+       *
+       * @param {string} name Event name to listen on.
+       * @param {function(event, args...)} listener Function to call when the event is emitted.
+       * @returns {function()} Returns a deregistration function for this listener.
        */
       $on: function(name, listener) {
         var namedListeners = this.$$listeners[name];