Add readme file for batch sample

Author: “Kevin”

cmd/samples/batch/README.md

@@ -0,0 +1,38 @@
+# Batch Processing Sample
+
+This sample demonstrates how to process large batches of tasks with controlled concurrency using Cadence's `x.NewBatchFuture` functionality.
+
+## What it does
+
+- Creates a configurable number of activities (default: 10)
+- Executes them with controlled concurrency (default: 3)
+- Simulates work with random delays (900-999ms per task)
+- Handles cancellation gracefully
+
+## Real-world use cases
+
+- Batch data processing
+- Bulk operations
+- ETL jobs
+- Report generation
+- File processing
+
+## How to run
+
+Start Worker:
+```bash
+./bin/batch -m worker
+```
+
+Start Workflow:
+```bash
+./bin/batch -m trigger
+```
+
+## Key concepts
+
+- **Batch processing**: Process multiple tasks efficiently
+- **Concurrency control**: Limit simultaneous executions
+- **Activity factories**: Lazy evaluation of activities
+- **Future-based execution**: Asynchronous task management
+- **Context cancellation**: Graceful handling of timeouts

cmd/samples/batch/main.go

@@ -35,7 +35,7 @@ func startWorkflow(h *common.SampleHelper) {
 
 	// Default batch configuration
 	input := BatchWorkflowInput{
-		Concurrency: 2,
+		Concurrency: 3,
 		TotalSize:   10,
 	}