improve error code reference (#1454)

lang/src/error.rs

@@ -10,6 +10,7 @@ pub const ERROR_CODE_OFFSET: u32 = 6000;
 /// - >= 2000 constraint error codes
 /// - >= 3000 account error codes
 /// - = 4000 state error code
+/// - >= 4100 misc error codes 
 /// - = 5000 deprecated error code
 ///
 /// The starting point for user-defined errors is defined