added marker interface option to service DSL

README.md

@@ -1,5 +1,5 @@
 [![coverage](https://coveralls.io/repos/daviddenton/protokruft/badge.svg?branch=master)](https://coveralls.io/github/daviddenton/protokruft?branch=master)
-[![kotlin](https://img.shields.io/badge/kotlin-1.2-blue.svg)](http://kotlinlang.org)
+[![kotlin](https://img.shields.io/badge/kotlin-1.3-blue.svg)](http://kotlinlang.org)
 [![build status](https://travis-ci.org/daviddenton/protokruft.svg?branch=master)](https://travis-ci.org/daviddenton/protokruft)
 [![bintray version](https://api.bintray.com/packages/daviddenton/maven/protokruft/images/download.svg)](https://bintray.com/daviddenton/maven/protokruft/_latestVersion)
 
@@ -101,6 +101,8 @@ val newBlockingStub = CarService.Grpc.Client(channel)
 val grpcService= CarService.Grpc.Server(myCarServiceImplementation)
 ```
 
+Optionally, you can also add a `markerInterface` option to aid IDE navigability.
+
 ## Use it:
 Merge the following sections into your Gradle file. This assumes that you've already got Protobuf classes being generated by the `protobuf-gradle-plugin`:
 ```groovy
@@ -122,6 +124,7 @@ Merge the following sections into your Gradle file. This assumes that you've alr
         messageDslPrefix = "customPrefix" // "new" by default
         serviceClassFile = "customService" // "serviceDsl" by default
         serviceDslSuffix = "CustomSuffix" // "" by default
+        markerInterface = "com.my.great.Interface" // null by default
     }
 
     // allows you to just run generateProtoDsl