fix: used singlequotes for lesson12.ts strings

advised by github

Author: AmiyahJo

lesson_12/structs_ts/src/lesson12.ts

@@ -1,7 +1,7 @@
 import { ListNode } from './list_node.js';
 
 export class Lesson12 {
-  
+
   public gameResult(head: ListNode | null): string {
     let [oddPoints, evenPoints] = [0,0];
     let current = head;
@@ -16,11 +16,11 @@ export class Lesson12 {
     }
 
     if (oddPoints > evenPoints) {
-      return "Odd";
+      return 'Odd';
     } else if (evenPoints > oddPoints) {
-      return "Even";
+      return 'Even';
     } else {
-      return "Tie";
+      return 'Tie';
     }
   }
 }