Fixes dotnet#1659

docs/fundamentals/dashboard/configuration.md

@@ -1,7 +1,7 @@
 ---
 title: .NET Aspire dashboard configuration
 description: .NET Aspire dashboard configuration options
-ms.date: 10/29/2024
+ms.date: 02/13/2025
 ms.topic: reference
 ---
 
@@ -74,6 +74,7 @@ Alternatively, these same values could be configured using a JSON configuration
 | `DOTNET_DASHBOARD_OTLP_HTTP_ENDPOINT_URL` | `http://localhost:18890` | The [OTLP/HTTP](https://opentelemetry.io/docs/specs/otlp/#otlphttp) endpoint. This endpoint hosts an OTLP service and receives telemetry using Protobuf over HTTP. When the dashboard is launched by the .NET Aspire app host the OTLP/HTTP endpoint isn't configured by default. To configure an OTLP/HTTP endpoint with the app host, set an `DOTNET_DASHBOARD_OTLP_HTTP_ENDPOINT_URL` env var value in _launchSettings.json_. Securing the dashboard with HTTPS is recommended. |
 | `DOTNET_DASHBOARD_UNSECURED_ALLOW_ANONYMOUS` | `false` | Configures the dashboard to not use authentication and accepts anonymous access. This setting is a shortcut to configuring `Dashboard:Frontend:AuthMode` and `Dashboard:Otlp:AuthMode` to `Unsecured`. |
 | `DOTNET_DASHBOARD_CONFIG_FILE_PATH` | `null` | The path for a JSON configuration file. If the dashboard is being run in a Docker container, then this is the path to the configuration file in a mounted volume. This value is optional. |
+| `DOTNET_DASHBOARD_FILE_CONFIG_DIRECTORY` | `null` | The directory where the dashboard looks for key-per-file configuration. This value is optional. |
 | `DOTNET_RESOURCE_SERVICE_ENDPOINT_URL` | `null` | The gRPC endpoint to which the dashboard connects for its data. If this value is unspecified, the dashboard shows telemetry data but no resource list or console logs. This setting is a shortcut to `Dashboard:ResourceServiceClient:Url`. |
 
 ## Frontend authentication