add welcome page for this project

Author: aserbao

app/src/main/AndroidManifest.xml

@@ -12,7 +12,7 @@
         android:allowBackup="true"
         android:debuggable="true"
         android:hardwareAccelerated="true"
-        android:icon="@mipmap/ic_launcher"
+        android:icon="@mipmap/ic_lanuch"
         android:label="@string/app_name"
         android:supportsRtl="true"
         android:theme="@style/MyTheme">

app/src/main/res/drawable-xxhdpi/welcome.jpg

@@ -7,7 +7,7 @@
     tools:context=".WelcomeActivity">
     <ImageView
         android:id="@+id/bgIV"
-        android:src="@drawable/bg"
+        android:src="@drawable/welcome"
         android:scaleType="fitXY"
         android:layout_width="match_parent"
         android:layout_height="match_parent"/>