implemented the delete completed function to delete all the tasks that has been completed

Author: Ebrahim-Moqbel

Sprint-3/todo-list/todos.mjs

@@ -26,4 +26,12 @@ export function toggleCompletedOnTask(todos, taskIndex) {
   if (todos[taskIndex]) {
     todos[taskIndex].completed = !todos[taskIndex].completed;
   }
-}
+}
+// remove all the completed tasks from the given list
+export function deleteCompleted(toDoList) {
+  for (let i = toDoList.length - 1; i >= 0; i--) {
+    if (toDoList[i].completed) {
+      deleteTask(toDoList, i);
+    }
+  }
+}