feat: minor usage improvements in root component

src/app/app.component.html

@@ -3,6 +3,9 @@
     <mat-icon>translate</mat-icon>
     angular-t9n
   </a>
+  <a mat-button matTooltip="Dashboard" routerLink="/">
+    <mat-icon>home</mat-icon>
+  </a>
   <span class="separator"></span>
   <mat-icon
     class="service-down-error"

src/app/app.component.scss

@@ -15,6 +15,7 @@
 
   main {
     opacity: 0.5;
+    pointer-events: none;
   }
 }
 

src/app/app.component.ts

@@ -1,4 +1,5 @@
 import { Component, HostBinding } from '@angular/core';
+import { MatSnackBar } from '@angular/material/snack-bar';
 
 import { TranslationService } from './core/translation.service';
 
@@ -10,7 +11,16 @@ import { TranslationService } from './core/translation.service';
 export class AppComponent {
   @HostBinding('class.service-down') serviceDown = false;
 
-  constructor(translationService: TranslationService) {
-    translationService.serviceDown.subscribe(a => (this.serviceDown = a));
+  constructor(translationService: TranslationService, snackbar: MatSnackBar) {
+    translationService.serviceDown.subscribe(a => {
+      this.serviceDown = a;
+      if (a) {
+        snackbar.open(
+          `Translation server is not available. Start the server in the console with the command 'ng run yourProject:t9n'`,
+          undefined,
+          { duration: 2500 }
+        );
+      }
+    });
   }
 }