docs: add docs for off(container)

Author: Narretz

src/ng/animate.js

@@ -326,6 +326,9 @@ var $AnimateProvider = ['$provide', function($provide) {
        * // remove all the animation event listeners listening for `enter`
        * $animate.off('enter');
        *
+       * // remove animation event listeners for all events from the container element
+       * $animate.off(container);
+       *
        * // remove all the animation event listeners listening for `enter` on the given element and its children
        * $animate.off('enter', container);
        *
@@ -334,7 +337,9 @@ var $AnimateProvider = ['$provide', function($provide) {
        * $animate.off('enter', container, callback);
        * ```
        *
-       * @param {string} event the animation event (e.g. enter, leave, move, addClass, removeClass, etc...)
+       * @param {string|DOMElement} event|container the animation event (e.g. enter, leave, move,
+       * addClass, removeClass, etc...), or the container element. If it is the element, all other
+       * arguments are ignored.
        * @param {DOMElement=} container the container element the event listener was placed on
        * @param {Function=} callback the callback function that was registered as the listener
        */