Add taskList addition system.

src/app/task-lists/task-lists.component.ts

@@ -0,0 +1,32 @@
+import { Component, OnInit } from '@angular/core';
+import { MatDialog } from '@angular/material/dialog';
+import { Observable, Subscription } from 'rxjs';
+import { TaskList } from '../core/entity/taskList';
+import { TaskListService } from '../core/service/task-list.service';
+import { AddNewListComponent } from './add-new-list/add-new-list.component';
+
+@Component({
+  selector: 'app-task-lists',
+  templateUrl: './task-lists.component.html',
+  styleUrls: ['./task-lists.component.scss']
+})
+export class TaskListsComponent implements OnInit {
+  taskLists$?: Observable<TaskList[]>;
+  private _taskListsSubscription?: Subscription;
+
+  constructor(
+    private _dialog: MatDialog,
+    private _taskListService: TaskListService
+  ) {}
+
+  ngOnInit(): void {
+    this.taskLists$ = this._taskListService.taskLists$;
+  }
+
+  addNewList(): void {
+    const dialogRef = this._dialog.open(AddNewListComponent);
+    dialogRef.afterClosed().subscribe(newList => {
+      this._taskListService.add(newList);
+    });
+  }
+}