(AzureCXP) fixes MicrosoftDocs/azure-docs#106781

Author: mumurug-MSFT

articles/azure-functions/functions-app-settings.md

@@ -365,6 +365,7 @@ Valid values:
 | `node` | [JavaScript](functions-reference-node.md)<br/>[TypeScript](functions-reference-node.md#typescript) |
 | `powershell` | [PowerShell](functions-reference-powershell.md) |
 | `python` | [Python](functions-reference-python.md) |
+| `custom` | [Custom](functions-custom-handlers.md) |
 
 ## FUNCTIONS\_WORKER\_SHARED\_MEMORY\_DATA\_TRANSFER\_ENABLED