added Update notification and button to download from Website

app/build.gradle

@@ -10,8 +10,8 @@ android {
         applicationId "de.joel.zoomhelper"
         minSdkVersion 21
         targetSdkVersion 30
-        versionCode 1
-        versionName '0.4.4'
+        versionCode 9
+        versionName '0.4.5'
 
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
@@ -28,6 +28,12 @@ android {
     }
 }
 
+repositories {
+    maven {
+        url "https://jitpack.io"
+    }
+}
+
 dependencies {
 
     implementation 'androidx.appcompat:appcompat:1.2.0'
@@ -37,4 +43,5 @@ dependencies {
     androidTestImplementation 'androidx.test.ext:junit:1.1.2'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
     implementation 'com.google.android.material:material:1.3.0'
+    implementation 'com.github.javiersantos:AppUpdater:2.7'
 }