Adds note to purge everything

Author: angelampcosta

src/content/docs/cache/how-to/purge-cache/purge-everything.mdx

@@ -15,6 +15,10 @@ Purging everything instantly clears all resources from your CDN cache in all Clo
 3. Under **Purge Cache**, select **Purge Everything**. A warning window appears.
 4. If you agree, select **Purge Everything**.
 
+:::note
+When purging everything for a non-production cache environment, all files for that specific cache environment will be purged. However, when purging everything for the production environment, all files will be purged across all environments.
+:::
+
 ## Resulting cache status
 
 Purge Everything invalidates the resource, resulting in the `CF-Cache-Status` header indicating [`EXPIRED`](/cache/concepts/cache-responses/#expired) for subsequent requests.