Doc Fix: azurerm_iothub_resource doc shows correct route source option names (hashicorp#14149)

Author: dmitrytokarev

website/docs/r/iothub.html.markdown

@@ -202,7 +202,7 @@ A `route` block supports the following:
 
 * `name` - (Required) The name of the route.
 
-* `source` - (Required) The source that the routing rule is to be applied to, such as `DeviceMessages`. Possible values include: `RoutingSourceInvalid`, `RoutingSourceDeviceMessages`, `RoutingSourceTwinChangeEvents`, `RoutingSourceDeviceLifecycleEvents`, `RoutingSourceDeviceConnectionStateEvents`, `RoutingSourceDeviceJobLifecycleEvents`.
+* `source` - (Required) The source that the routing rule is to be applied to, such as `DeviceMessages`. Possible values include: `Invalid`, `DeviceMessages`, `TwinChangeEvents`, `DeviceLifecycleEvents`, `DeviceConnectionStateEvents`, `DeviceJobLifecycleEvents`.
 
 * `condition` - (Optional) The condition that is evaluated to apply the routing rule. If no condition is provided, it evaluates to true by default. For grammar, see: https://docs.microsoft.com/azure/iot-hub/iot-hub-devguide-query-language.
 
@@ -224,7 +224,7 @@ An `enrichment` block supports the following:
 
 A `fallback_route` block supports the following:
 
-* `source` - (Optional) The source that the routing rule is to be applied to, such as `DeviceMessages`. Possible values include: `RoutingSourceInvalid`, `RoutingSourceDeviceMessages`, `RoutingSourceTwinChangeEvents`, `RoutingSourceDeviceLifecycleEvents`, `RoutingSourceDeviceConnectionStateEvents`, `RoutingSourceDeviceJobLifecycleEvents`.
+* `source` - (Optional) The source that the routing rule is to be applied to, such as `DeviceMessages`. Possible values include: `Invalid`, `DeviceMessages`, `TwinChangeEvents`, `DeviceLifecycleEvents`, `DeviceConnectionStateEvents`, `DeviceJobLifecycleEvents`.
 
 * `condition` - (Optional) The condition that is evaluated to apply the routing rule. If no condition is provided, it evaluates to true by default. For grammar, see: https://docs.microsoft.com/azure/iot-hub/iot-hub-devguide-query-language.