Mention WebJarsResourceResolver in ref doc

Issue: SPR-12323

Author: bclozel

src/asciidoc/web-mvc.adoc

@@ -5026,7 +5026,12 @@ the response `encodeURL` method. Alternatively, an application can also inject a
 use directly the `ResourceUrlProvider` bean, which is automatically declared with the MVC
 Java config and the MVC namespace.
 
-
+Webjars are also supported with `WebJarsResourceResolver`, which is automatically registered
+when the ``"org.webjars:webjars-locator"` library is on classpath. This resolver allows
+the resource chain to resolve version agnostic libraries from HTTP GET requests
+`"GET /jquery/jquery.min.js" will return resource "/jquery/1.2.0/jquery.min.js"`.
+It also works by rewriting resource URLs in templates
+`<script src="/jquery/jquery.min.js"/> -> <script src="/jquery/1.2.0/jquery.min.js"/>`.
 
 
 [[mvc-default-servlet-handler]]