Clarify how to use urlpattern matching (#882)

Author: ntotten

docs/articles/advanced-path-matching.mdx

@@ -16,6 +16,27 @@ However, you can opt to use a more advanced path matching approach based on the
 web standard
 [URLPattern](https://developer.mozilla.org/en-US/docs/Web/API/URLPattern).
 
+In order to use URLPattern matching you must set your route's
+`x-zuplo-path.pathMode` to `url-pattern`.
+
+The URLPattern matching mode can be set in the UI as shown below:
+
+![Route ](../../public/media/advanced-path-matching/image.png)
+
+Alternatively, you can set it in your OpenAPI file as follows:
+
+```json {4-6} title="config/routes.oas.json"
+{
+  "paths": {
+    "/files/:path*": {
+      "x-zuplo-path": {
+        "pathMode": "url-pattern"
+      }
+    }
+  }
+}
+```
+
 The most basic path is `/` which will simple match the root path. You can add
 other static paths like `/foo` and `/foo/bar`