Add button to show task addition pane.

src/app/app.module.ts

@@ -6,6 +6,8 @@ import { AppRoutingModule } from './app-routing.module';
 import { AppComponent } from './app.component';
 import { MainPageComponent } from './main-page/main-page.component';
 import { AddTaskComponent } from './add-task/add-task.component';
+import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
+import {MatIconModule} from '@angular/material/icon'; 
 
 @NgModule({
   declarations: [
@@ -15,11 +17,12 @@ import { AddTaskComponent } from './add-task/add-task.component';
   ],
   imports: [
     BrowserModule,
-    AppRoutingModule
+    AppRoutingModule,
+    BrowserAnimationsModule,
+    MatIconModule
   ],
   providers: [
     CookieService,
-    
   ],
   bootstrap: [AppComponent]
 })