[Web Bot Auth] Update documentation in web-bot-auth.mdx (cloudflare#23335)

* [Web Bot Auth] Update documentation in web-bot-auth.mdx

- Resolves cloudflare#23334

* Update src/content/docs/bots/concepts/bot/verified-bots/web-bot-auth.mdx

Co-authored-by: Kody Jackson <[email protected]>

* Update src/content/docs/bots/concepts/bot/verified-bots/web-bot-auth.mdx

Co-authored-by: Kody Jackson <[email protected]>

---------

Co-authored-by: Kody Jackson <[email protected]>

Author: 2 people

src/content/docs/bots/concepts/bot/verified-bots/web-bot-auth.mdx

@@ -187,6 +187,12 @@ Signature-Input: sig2=("@authority" "signature-agent")
 Signature: sig2=:jdq0SqOwHdyHr9+r5jw3iYZH6aNGKijYp/EstF4RQTQdi5N5YYKrD+mCT1HA1nZDsi6nJKuHxUi/5Syp3rLWBA==:
 ```
 
+:::note
+You can test how Cloudflare interprets your signed requests against https://crawltest.com/cdn-cgi/web-bot-auth. This endpoint returns 
+an HTTP `401` if your message is formatted correctly but your key is unknown, an HTTP `200` if the key is known and your message is verified, 
+and an HTTP `400` otherwise. You may also see an HTTP `401` if your key is known but the message failed to verify.
+:::
+
 ## Additional resources
 
 You may wish to refer to the following resources.