[Docs] Mention Anyscale platform provids e2e fault tolerance (#50274)

Per request from: @brent-anyscale 

## Related issue number
[Jira
issue](https://anyscale1.atlassian.net/browse/MLDX-468?atlOrigin=eyJpIjoiYjg3ODBkZDQ4MGMyNDUwNmJmMzU3NjQ2OWJkMzgyOGUiLCJwIjoiamlyYS1zbGFjay1pbnQifQ)

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Signed-off-by: angelinalg <[email protected]>

doc/source/serve/production-guide/fault-tolerance.md

@@ -17,7 +17,9 @@ This section discusses concepts from:
 (serve-e2e-ft-guide)=
 ## Guide: end-to-end fault tolerance for your Serve app
 
-Serve provides some [fault tolerance](serve-ft-detail) features out of the box. You can provide end-to-end fault tolerance by tuning these features and running Serve on top of [KubeRay].
+Serve provides some [fault tolerance](serve-ft-detail) features out of the box. Two options to get end-to-end fault tolerance are the following:
+* tune these features and run Serve on top of [KubeRay]
+* use the [Anyscale platform](https://docs.anyscale.com/platform/services/head-node-ft), a managed Ray platform
 
 ### Replica health-checking