fix 415 error to add data

src/GreenHome.Api/Controllers/TelemetryController.cs

@@ -25,7 +25,7 @@ public class TelemetryController : ControllerBase
     }
 
     [HttpGet("AddData")]
-    public async Task<ActionResult<int>> Create(object deviceName, decimal temperatureC, decimal humidityPercent, 
+    public async Task<ActionResult<int>> Create(string deviceName, decimal temperatureC, decimal humidityPercent, 
         decimal soilPercent, int gasPPM, decimal lux, CancellationToken cancellationToken)
     {