Update README.md

Author: tnkshuuhei

Diff for: README.md

@@ -1,4 +1,53 @@
-## Hypercerts Periphery Contracts
+# Hypercerts Periphery Contracts
 
 [![TEST](https://github.com/hypercerts-org/protocol-periphery/actions/workflows/test.yml/badge.svg)](https://github.com/hypercerts-org/protocol-periphery/actions/workflows/test.yml)
 [![Slither Analysis](https://github.com/hypercerts-org/protocol-periphery/actions/workflows/slither.yaml/badge.svg)](https://github.com/hypercerts-org/protocol-periphery/actions/workflows/slither.yaml)
+
+## Implementation
+
+### BatchTransferFraction
+```mermaid
+sequenceDiagram
+actor o as Owner
+participant h as Hypercert Minter Contract
+participant b as BatchTransfer Contract
+actor r as Recipients
+
+o ->> h: call splitFraction()
+h ->> h: split fraction
+o ->> h: call setApprovalForAll()
+o ->> b: call batchTransfer()
+critical will be reverted if the owner is not the owner of each fractions
+b --> h: check if caller is the owner of fraction
+b ->> r: safeTransferFrom()
+end
+
+```
+```solidity
+    /// @dev msg.sender must be the owner of all the fraction IDs being transferred
+    /// @dev msg.sender must have approved the contract to transfer the fractions
+    /// @dev The length of recipients and fractionIds must be the same
+    /// @param data The encoded data containing the recipients and fraction IDs
+    function batchTransfer(bytes memory data) external {
+        require(data.length > 0, INVALID_DATA());
+        TransferData memory transferData = abi.decode(data, (TransferData));
+        require(transferData.recipients.length == transferData.fractionIds.length, INVALID_LENGTHS());
+
+        _batchTransfer(transferData.recipients, transferData.fractionIds);
+    }
+
+    /// @notice Transfers fractions to multiple recipients
+    /// @dev The length of recipients and fractionIds must be the same
+    /// @dev The caller must be the owner of all the fraction IDs being transferred
+    /// @param recipients The addresses of the recipients
+    /// @param fractionIds The IDs of the fractions to be transferred
+    function _batchTransfer(address[] memory recipients, uint256[] memory fractionIds) internal {
+        for (uint256 i = 0; i < recipients.length; i++) {
+            address recipient = recipients[i];
+            uint256 fractionId = fractionIds[i];
+            require(hypercertToken.ownerOf(fractionId) == msg.sender, INVALID_CALLER(msg.sender));
+
+            hypercertToken.safeTransferFrom(msg.sender, recipient, fractionId, 1, "");
+        }
+    }
+```