Android release docs

website/docs/modules/ROOT/nav.adoc

@@ -36,6 +36,7 @@
 * Experimental Platform Support
 ** Building Android Apps
 *** xref:android/android-initial-setup.adoc[]
+*** xref:android/android-release.adoc[]
 *** xref:android/ide.adoc[]
 *** xref:android/java.adoc[]
 *** xref:android/kotlin.adoc[]

website/docs/modules/ROOT/pages/android/android-initial-setup.adoc

@@ -57,28 +57,4 @@ If you want to start with an example project, you can use the `init` command as
 == 4. Use Android Studio
 You can use Android Studio to open and work with your Mill project.
 
-image::android/AndroidStudio.png[AndroidStudio.png]
-
-== 5. Release the project
-By default, mill projects are considered in debug mode, so if your project is ready for release, you should add the following to your app object in the `build.mill` file:
-
-[source,scala]
-----
-override def androidIsDebug = Task { false }
-def androidReleaseKeyName: Option[String] = Some("releaseKey.jks")
-def androidReleaseKeyAlias: T[Option[String]] = Task { Some("releaseKey") }
-def androidReleaseKeyPass: T[Option[String]] = Task { Some("MillBuildTool") }
-def androidReleaseKeyStorePass: T[Option[String]] = Task { Some("MillBuildTool") }
-----
-
-Make sure to replace the values with your actual keystore information.
-If you don't have a keystore yet, you can create one using the `keytool` command:
-
-[,console]
-----
-> keytool -genkey -v -keystore releaseKey.jks \
-          -storepass <PASS> -keyalg RSA \
-          -keysize 2048 -validity 10000 \
-          -alias releaseKey -keypass <PASS>
-----
-
+image::android/AndroidStudio.png[AndroidStudio.png]

website/docs/modules/ROOT/pages/android/android-release.adoc

@@ -0,0 +1,58 @@
+= Android Release Guide
+:page-aliases: android_release.adoc
+
+By default, mill projects are considered in debug mode, so if your project is ready for release, you should follow the steps below to configure your project for release builds.
+
+The code snippets below should be added to your app object in the `build.mill` file.
+
+== 1. Disable debug mode
+[source,scala]
+----
+def androidIsDebug = Task { false }
+----
+
+== 2. Configure signing information
+To sign your APK for release, you need to provide the keystore information.
+[source,scala]
+----
+def androidReleaseKeyName: Option[String] = Some("releaseKey.jks")
+def androidReleaseKeyAlias: T[Option[String]] = Task { Some("releaseKey") }
+def androidReleaseKeyPass: T[Option[String]] = Task.Input { Task.env.get("KEY_PASS") }
+def androidReleaseKeyStorePass: T[Option[String]] = Task.Input { Task.env.get("KEYSTORE_PASS") }
+----
+
+Make sure to replace the values with your actual keystore information.
+If you don't have a keystore yet, you can create one using the `keytool` command:
+
+[,console]
+----
+> keytool -genkey -v -keystore releaseKey.jks \
+          -storepass $KEYSTORE_PASS -keyalg RSA \
+          -keysize 2048 -validity 10000 \
+          -alias releaseKey -keypass $KEY_PASS
+----
+
+== 3. (Optional) Enable ProGuard
+If you want to enable ProGuard for code shrinking and obfuscation, you can do so by first extending your app object with `AndroidR8AppModule`.
+You can then override the following methods.
+
+Example configuration:
+[source,scala]
+----
+def androidReleaseSettings = Task {
+  AndroidBuildTypeSettings(
+    isMinifyEnabled = true,
+  )
+}
+
+// You can specify your own ProGuard rules files here
+def androidProjectProguardFiles = Task.Sources("proguard-rules.pro")
+
+// You can specify the default ProGuard filenames to be used
+// These files are in /<sdk_path>/tools/proguard/proguard*.txt
+def androidDefaultProguardFileNames = Task.Anon {
+  Seq("proguard-android-optimize.txt")
+}
+----
+
+