docs($resource): encode ) in link

JSDoc to HTML converter was treating the close parenthesis in
`[MDN](...#toJson()_behavior)` as the final close parenthesis, thus resulting in
a broken link.
This commit fixes it by percent-encoding the parentesis in the link address.

Closes #15825

Author: BobChao87

src/ngResource/resource.js

@@ -280,7 +280,7 @@ function shallowClearAndCopy(src, dst) {
  *     the Resource API. This object can be serialized through {@link angular.toJson} safely
  *     without attaching Angular-specific fields. Notice that `JSON.stringify` (and
  *     `angular.toJson`) automatically use this method when serializing a Resource instance
- *     (see [MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify#toJSON()_behavior)).
+ *     (see [MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify#toJSON%28%29_behavior)).
  *
  * @example
  *