docs($compileProvider): improve strictComponentBindingsEnabled info

Related to angular#16303 
Closes angular#16306

docs/content/error/$compile/missingattr.ngdoc

@@ -3,6 +3,34 @@
 @fullName Missing required attribute
 @description
 
-This error may occur only when `$compileProvider.strictComponentBindingsEnabled` is set to `true`.
-Then all attributes mentioned in `bindings` without `?` must be set. If one or more aren't set,
-the first one will throw an error.
+This error may occur only when {@link $compileProvider#strictComponentBindingsEnabled `$compileProvider.strictComponentBindingsEnabled`} is set to `true`.
+
+If that is the case, then all {@link $compileProvider#component component} controller bindings and
+{@link $compileProvider#directive directive} scope / controller bindings that are non-optional,
+must be provided when the directive is instantiated.
+
+To make a binding optional, add '?' to the definition.
+
+## Example:
+
+```js
+
+app.component('myTest', {
+  bindings: {
+    first: '=?', // optional
+    second: '='
+  },
+  controller: function() {
+    ...
+  },
+  template: '...'
+});
+
+```
+
+This component will throw `missingattr` for the `second` binding when used as follows:
+
+```html
+<my-test></my-test>
+```
+

src/ng/compile.js

@@ -1415,16 +1415,19 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
    * @ngdoc method
    * @name  $compileProvider#strictComponentBindingsEnabled
    *
-   * @param {boolean=} enabled update the strictComponentBindingsEnabled state if provided, otherwise just return the
-   * current strictComponentBindingsEnabled state
+   * @param {boolean=} enabled update the strictComponentBindingsEnabled state if provided,
+   * otherwise return the current strictComponentBindingsEnabled state.
    * @returns {*} current value if used as getter or itself (chaining) if used as setter
    *
    * @kind function
    *
    * @description
-   * Call this method to enable/disable strict component bindings check. If enabled, the compiler will enforce that
-   * for all bindings of a component that are not set as optional with `?`, an attribute needs to be provided
-   * on the component's HTML tag.
+   * Call this method to enable / disable the strict component bindings check. If enabled, the
+   * compiler will enforce that all scope / controller bindings of a
+   * {@link $compileProvider#directive directive} / {@link $compileProvider#component component}
+   * that are not set as optional with `?`, must be provided when the directive is instantiated.
+   * If not provided, the compiler will throw the
+   * {@link error/$compile/missingattr $compile:missingattr error}.
    *
    * The default value is false.
    */