chore: Show how to override dev IP (#359)

src/content/docs/troubleshooting.mdx

@@ -79,6 +79,25 @@ Then create an API route at `/pages/healthz.js`:
 
 When you deploy your app next, Arcjet should not trigger on this route.
 
+### Override development IP
+
+Arcjet's [IP geolocation](/blueprints/ip-geolocation) and [VPN & proxy
+detection](/blueprints/vpn-proxy-detection) features require a real IP address
+to work. In local development, Arcjet defaults to `127.0.0.1` so the IP analysis
+metadata will be empty.
+
+You can set the IP address to a real public IP by overriding the IP address
+field (`ip`) in the `request` object that is passed to the Arcjet `protect`
+function.
+
+```ts
+// Override the IP address in the request object if `ip` is provided. You could
+// set this using an environment variable or some other method to ensure it is
+// only set in development.
+//const ip = "8.8.8.8"; // Google's public DNS server
+const decision = await aj.protect(ip ? { ...req, ip } : req);
+```
+
 ## Common errors
 
 ### [unauthenticated] invalid key