feat: minor fixes

Author: Yash Agrawal

contracts/SBTToken.sol

@@ -12,16 +12,16 @@ contract SBTToken is ISBTToken, ERC721EnumerableUpgradeable {
 	using Base64 for bytes;
 	using Strings for uint256;
 
-	/// @dev EOA with minting rights.
-	address private _minter;
 	/// @dev Account with proxy adming rights.
 	address private _proxyAdmin;
 
+	/// @dev EOA with minting rights.
+	mapping(address => bool) private _minters;
 	/// @dev Holds the encoded metadata of a SBT token.
 	mapping(uint256 => bytes) private _sbtdata;
 
 	modifier onlyMinter() {
-		require(_minter == _msgSender(), "Illegal access");
+		require( _minters[_msgSender()], "Illegal access");
 		_;
 	}
 
@@ -51,9 +51,12 @@ contract SBTToken is ISBTToken, ERC721EnumerableUpgradeable {
 		}
 	}
 
-	function initialize(address minter) external initializer {
+	function initialize(address[] memory minters) external initializer {
 		__ERC721_init("Dev Protocol SBT V1", "DEV-SBT-V1");
-		_minter = minter;
+
+		for (uint256 i = 0; i < minters.length; i++) {
+			_minters[minters[i]] = true;
+		}
 	}
 
 	function setProxyAdmin(address proxyAdmin) external {