Update managed-robots-txt.mdx (#23205)

* Update managed-robots-txt.mdx

* Apply suggestions from code review

---------

Co-authored-by: Patricia Santa Ana <[email protected]>

Author: amartinetticf

src/content/docs/bots/additional-configurations/managed-robots-txt.mdx

@@ -14,6 +14,10 @@ Cloudflare's managed `robots.txt` explicitly disallows known bots engaged in scr
 
 AI bots are expected to follow the `robots.txt` directives. Otherwise, they risk getting banned. 
 
+## Compatibility with existing `robots.txt` files
+
+Cloudflare will indepedently check whether your website has an existing `robots.txt` file. If your website already has one — verified by a HTTP `200` response — we will prepend our managed `robots.txt` before your existing `robots.txt`, combining both into a single response. 
+
 To implement a `robots.txt` file on your domain based on your plan:
 
 <Tabs>
@@ -28,9 +32,5 @@ To implement a `robots.txt` file on your domain based on your plan:
   </TabItem>
 </Tabs>
 
-:::note
-When you enable the `robots.txt` file on your domain, existing `robots.txt` files will be replaced.
-:::
-
 ## Availability
 Managed `robots.txt` for AI crawlers is available on all plans.