Usage in README

README.md

@@ -3,3 +3,23 @@
 [![Build Status](https://travis-ci.org/NeQuissimus/circe-kafka.svg?branch=master)](https://travis-ci.org/NeQuissimus/circe-kafka)
 
 Implicitly turn your `Encoder` and `Decoder` instances into `Serializer`, `Deserializer` and `Serde`.
+
+## Usage
+
+```scala
+import io.circe.{ Decoder, Encoder }
+import org.apache.kafka.common.serialization.{ Deserializer, Serde, Serializer }
+
+final case class Foo(i: Int)
+
+//
+
+import com.nequissimus.circe.kafka._
+
+implicit val encoder: Encoder[Foo] = ... // for example by importing io.circe.generic.auto._
+implicit val decoder: Decoder[Foo] = ...
+
+val serializer: Serializer[Foo] = implicitly
+val deserializer: Deserializer[Foo] = implicitly
+val serde: Serde[Foo] = implicitly
+```