added Update notification and button to download from Website

app/src/main/java/de/joel/zoomhelper/MainActivity.java

@@ -19,6 +19,9 @@ import android.widget.Toast;
 import androidx.appcompat.app.AlertDialog;
 import androidx.appcompat.app.AppCompatActivity;
 
+import com.github.javiersantos.appupdater.AppUpdater;
+import com.github.javiersantos.appupdater.enums.UpdateFrom;
+
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.EOFException;
@@ -80,6 +83,12 @@ public class MainActivity extends AppCompatActivity {
         watchDeleteIcon();
         watchNewIcon();
         watchShareIcon();
+
+
+        AppUpdater appUpdater = new AppUpdater(this).setUpdateFrom(UpdateFrom.XML).setUpdateXML("https://baldaufwd.de/ZoomHelper/update.xml");
+
+        appUpdater.start();
+
     }
 
     private void watchShareIcon() {