Add test into to readme

README.md

@@ -6,3 +6,14 @@ This project is a minnimum reproducible repo that aims to replicate a problem th
 
 Website: https://api-demo-94c7a.web.app
 API: https://api-cdn-cache.web.app
+
+## Testing
+
+A testing script has been created to show that the responses are cached (specifically 404s) by checking the response headers.
+Note that no `Cache Control` header is present in the response.
+
+Our observations show that specifically GET 404 responses are the ones that get cached. To further support this investigation, we can purge the cache with the following request:
+
+```
+curl -X PURGE https://api-cdn-cache.web.app/date
+```