update separate

lib/extension/separate_extension.dart

@@ -1,6 +1,7 @@
 import 'package:ansu_ui/ansu_ui.dart';
-extension SeparateExt<T> on List<T> {
-  List<T> sep([T separate]) {
+import 'package:flutter/material.dart';
+extension SeparateExt on List {
+  List<Widget> sep([Widget separate]) {
     return List.generate(this.length * 2 - 1, (index) {
       if (index.isEven)
         return this[index ~/ 2];