Update cloudflare-ray-id.mdx

Due to Argo Smart Routing, the colo portion may differ between Request and Response headers, making the full string potentially change if evaluated.

Author: cf-scott

src/content/docs/fundamentals/reference/cloudflare-ray-id.mdx

@@ -3,7 +3,7 @@ pcx_content_type: reference
 title: Cloudflare Ray ID
 ---
 
-A **Cloudflare Ray ID** is an identifier given to every request that goes through Cloudflare.
+A **Cloudflare Ray ID** is an identifier given to every request that goes through Cloudflare. The Ray ID is the hash portion of the Cf-Ray HTTP Header. The header will include colo information after the Ray ID.
 
 Ray IDs are particularly useful when evaluating Security Events for patterns or false positives or more generally understanding your application traffic.