added kotlin instructions

README.md

@@ -24,10 +24,42 @@ For Android, you must do the following before you can use the plugin:
      
      `<uses-permission android:name="android.permission.CAMERA" />`
 
-* Add the Barcode activity to your AndroidManifest.xml
+* Add the BarcodeScanner activity to your AndroidManifest.xml. Do NOT modify the name.
     
      `<activity android:name="com.apptreesoftware.barcodescan.BarcodeScannerActivity"/>`
      
+
+* This plugin is written in Kotlin. Therefore, you need to add Kotlin support to your project. See [installing the Kotlin plugin](https://kotlinlang.org/docs/tutorials/kotlin-android.html#installing-the-kotlin-plugin).
+
+Edit your project-level build.gradle file to look like this:
+
+	buildscript {
+	    ext.kotlin_version = '1.2.31'
+	    ...
+	    dependencies {
+	        ...
+	        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+	    }
+	}
+	...
+
+Edit your app-level build.gradle file to look like this:
+
+	apply plugin: 'kotlin-android'
+	...
+	dependencies {
+	    implementation "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
+	    ...
+	}
+
+Now you can depend on the barcode_scan plugin in your pubspec.yaml file:
+
+	dependencies:
+	  ...
+	  barcode_scan: ^0.0.3
+
+Click "Packages get" in Android Studio or run `flutter packages get` in your project folder.
+
 ### iOS
 To use on iOS, you must add the the camera usage description to your Info.plist