docs(input[checkbox]): add ngChecked

src/ng/directive/input.js

@@ -1098,6 +1098,8 @@ var inputType = {
    *                  Can be interpolated.
    * @param {string=} ngChange Angular expression to be executed when the ngModel value changes due
    *                  to user interaction with the input element.
+   * @param {expression=} ngChecked If the expression is truthy, then the `checked` attribute will be set on the element.
+   *    **Note** : ngChecked should not be used alongside ngModel. Checkout {@link api/ng/directive/ngChecked ngChecked} for usage.
    *
    * @example
       <example name="range-input-directive" module="rangeExample">