Corrected website warmup information and added refs to settings

Corrected website warmup information where it incorrectly stated 5xx responses are not considered a warmed up site. Added refereces to WEBSITE_WARMUP_PATH and WEBSITE_WARMUP_STATUSES.

Author: adamkimsft

support/azure/app-service/faqs-app-service-linux.yml

@@ -250,7 +250,8 @@ sections:
       - question: |
           How does the container warmup request work?
         answer: |
-          When Azure App Services starts your container, the warmup request sends an HTTP request to the [/robots933456.txt](/azure/app-service/configure-custom-container?pivots=container-linux#robots933456-in-logs) endpoint of your application. This is simply a dummy endpoint, but your application needs to reply with any non-5XX status code. If your application logic doesn't reply with any HTTP status code to nonexistent endpoints, the warmup request can't receive a response and it perpetually restarts your container.
+          When Azure App Services starts your container, the warmup request sends an HTTP request to the [/robots933456.txt](/azure/app-service/configure-custom-container?pivots=container-linux#robots933456-in-logs) endpoint of your application. This is simply a dummy endpoint, but your application needs to reply with any status code (including 5xx). If your application logic doesn't reply with any HTTP status code to nonexistent endpoints, the warmup request can't receive a response and it perpetually restarts your container.
+          The warmup endpoint path and the status codes that consider the site warmed-up can be customized from the default behavior by setting the [WEBSITE_WARMUP_PATH](https://learn.microsoft.com/en-us/azure/app-service/reference-app-settings?tabs=kudu%2Cdotnet#:~:text=WEBSITE_WARMUP_PATH) and [WEBSITE_WARMUP_STATUSES](https://learn.microsoft.com/en-us/azure/app-service/reference-app-settings?tabs=kudu%2Cdotnet#:~:text=WEBSITE_WARMUP_STATUSES) application settings.
           The warmup request also might fail due to port misconfiguration. 
           
           To ensure that the port is correctly configured on Azure App Services, see the question *How do I specify port in my Linux container?*