docs($compile): add docs for bindToController with object hash

Closes #13228
Closes #13625
Closes #13658
Closes #13681

src/ng/compile.js

@@ -212,10 +212,23 @@
  *
  *
  * #### `bindToController`
- * When an isolate scope is used for a component (see above), and `controllerAs` is used, `bindToController: true` will
+ * This property is used to bind scope properties directly to the controller. It can be either
+ * `true` or an object hash with the same format as the `scope` property. Additionally, a controller
+ * alias must be set, either by using `controllerAs: 'myAlias'` or by specifying the alias in the controller
+ * definition: `controller: 'myCtrl as myAlias'`.
+ *
+ * When an isolate scope is used for a directive (see above), `bindToController: true` will
  * allow a component to have its properties bound to the controller, rather than to scope. When the controller
  * is instantiated, the initial values of the isolate scope bindings will be available if the controller is not an ES6 class.
  *
+ * It is also possible to set `bindToController` to an object hash with the same format as the `scope` property.
+ * This will set up the scope bindings to the controller directly. Note that `scope` can still be used
+ * to define which kind of scope is created. By default, no scope is created. Use `scope: {}` to create an isolate
+ * scope (useful for component directives).
+ *
+ * If both `bindToController` and `scope` are defined and have object hashes, `bindToController` overrides `scope`.
+ *
+ *
  * #### `controller`
  * Controller constructor function. The controller is instantiated before the
  * pre-linking phase and can be accessed by other directives (see