update readme

Author: k-okawa

README.md

@@ -1 +1,112 @@
-# UniTaskObjectPool
+# UniTaskObjectPool
+
+ObjectPool for UniTask.
+
+AsyncObjectPool in this package conform to [UnityEngine.Pool.ObjectPool<T>](https://docs.unity3d.com/ScriptReference/Pool.ObjectPool_1.html)
+
+Differences is bellow
+
+- Create, OnGet and OnRelease return value is UniTask
+- Create, OnGet and OnRelease argument includes CancellationToken
+
+## Installation
+### Dependency
+Using UniTask in the package, UniTask must be added in the project.
+
+[UniTask](https://github.com/Cysharp/UniTask)
+
+### PackageManager
+
+#### Install via git url
+
+Open Window/Package Manager, and add package from git URL...
+
+```
+https://github.com/k-okawa/UniTaskObjectPool.git?path=Assets/Bg/UniTaskObjectPool
+```
+
+#### Install via OpenUPM
+
+```
+openupm add com.bg.unitaskobjectpool
+```
+
+### UnityPackage
+
+You can download unity package in [release page](https://github.com/k-okawa/UniTaskObjectPool/releases).
+
+## Sample Code
+
+```csharp
+public class SamplePoolObj : IDisposable
+{
+    public static int globalIndex = 0;
+    public readonly int id;
+    
+    public SamplePoolObj()
+    {
+        id = ++globalIndex;
+    }
+    
+    public async UniTask GetLog(CancellationToken ct)
+    {
+        await UniTask.Delay(TimeSpan.FromSeconds(0.02f), cancellationToken: ct);
+        Debug.Log($"Get from pool id:{id}");
+    }
+    
+    public async UniTask ReleaseLog(CancellationToken ct)
+    {
+        await UniTask.Delay(TimeSpan.FromSeconds(0.02f), cancellationToken: ct);
+        Debug.Log($"Release id:{id}");
+    }
+
+    public void Dispose()
+    {
+        Debug.Log($"Disposed id:{id}");
+    }
+}
+
+public static async UniTask<SamplePoolObj> CreateFunc(CancellationToken ct)
+{
+    await UniTask.Delay(TimeSpan.FromSeconds(0.02f), cancellationToken: ct);
+    return new SamplePoolObj();
+}
+
+public static UniTask OnGet(SamplePoolObj element, CancellationToken ct)
+{
+    return element.GetLog(ct);
+}
+
+public static UniTask OnRelease(SamplePoolObj element, CancellationToken ct)
+{
+    return element.ReleaseLog(ct);
+}
+
+public static void Destroy(SamplePoolObj element)
+{
+    element.Dispose();
+}
+```
+
+
+```csharp
+public async UniTask Sample(CancellationToken ct) 
+{
+    var objectPool = new AsyncObjectPool<SamplePoolObj>(
+                    CreateFunc,
+                    OnGet,
+                    OnRelease,
+                    Destroy,
+                    true, 10, 100
+                );
+    
+    var element = await objectPool.Get(ct);
+    await objectPool.Release(element, ct);
+    
+    var pooledObject = await objectPool.GetPooledObject(ct);
+    // call element function sample
+    await pooledObject.Get().GetLog(ct);
+    // return to pool
+    await pooledObject.DisposeAsync(ct);
+}
+```