Add ignoreAttributes to the documentation

Author: lamasfoker

routing.rst

@@ -1367,6 +1367,8 @@ Use the ``RedirectController`` to redirect to other routes and URLs:
                 # * for temporary redirects, it uses the 307 status code instead of 302
                 # * for permanent redirects, it uses the 308 status code instead of 301
                 keepRequestMethod: true
+                # add this to remove the parameters when redirecting
+                ignoreAttributes: true
 
         legacy_doc:
             path: /legacy/doc