chore: add readme

Author: twsc-james

ReadMe.md

@@ -0,0 +1,32 @@
+# EccSDK 
+EccSDK is a library that provides a simple way to interact with Chameleon Hash based on the ECC API.
+
+## Usage
+```csharp
+var keyPair = EccKeyPair.GenerateKeyPair();
+
+var signature = ChameleonHashHelper.Sign(new ChameleonHashRequest
+{
+    KeyPair = _keyPair,
+    Message = "Hello World",
+    Order = keyPair.PublicKey.Curve.Order,
+    SessionKey = new BigInteger("1234567890")
+});
+
+var chameleonHash = ChameleonHashHelper.GetChameleonHash(new ChameleonHashRequest
+{
+    KeyPair = _keyPair,
+    Message = "Hello World",
+    Order = keyPair.PublicKey.Curve.Order,
+    SessionKey = new BigInteger("1234567890"),
+    Signature = sign
+});
+
+var result = ChameleonHashHelper.Verify(new ChameleonHashRequest
+{
+    KeyPair = _keyPair,
+    Message = "Hello World",
+    Order = keyPair.PublicKey.Curve.Order,
+    Signature = sign
+}, chameleonHash);
+```