[docs] Add workflows to .NET client doc

daprdocs/content/en/dotnet-sdk-docs/dotnet-client/_index.md

@@ -199,12 +199,35 @@ await foreach (var items in subscribeConfigurationResponse.Source.WithCancellati
 }
 ```
 
+### Manage workflow instances (Alpha)
+
+```csharp
+var daprClient = new DaprClientBuilder().Build();
+
+string instanceId;
+string workflowComponentName;
+string workflowName;
+object input ;
+Dictionary<string, string> workflowOptions; // This is an optional parameter
+CancellationToken.None;
+
+// Start workflow
+var startResponse = await daprClient.StartWorkflowAsync(instanceId, workflowComponent, workflowName, input, workflowOptions, cts);
+
+// Terminate workflow
+await daprClient.TerminateWorkflowAsync(instanceId, workflowComponent);
+
+// Get workflow metadata
+var getResponse = await daprClient.GetWorkflowAsync(instanceId, workflowComponent, workflowName);
+```
+
 ## Sidecar APIs
 ### Sidecar Health
 The .NET SDK provides a way to poll for the sidecar health, as well as a convenience method to wait for the sidecar to be ready.
 
 #### Poll for health
 This health endpoint returns true when both the sidecar and your application are up (fully initialized).
+
 ```csharp
 var client = new DaprClientBuilder().Build();