add install and usage to readme

README.md

@@ -1,2 +1,133 @@
 # titan
+
 Event Listener for Go using Kafka
+
+### Install
+
+```
+go get github.com/ramadani/titan
+```
+
+### Dependencies
+
+- github.com/Shopify/sarama
+
+### Usage
+
+#### Emitter
+
+Create event 
+
+```go
+type userRegistration struct {
+	Name  string `json:"name"`
+	Email string `json:"email"`
+}
+
+type userRegisteredEvent struct {
+	data *userRegistration
+}
+
+func (u userRegisteredEvent) Header() string {
+	return "userRegistered"
+}
+
+func (u userRegisteredEvent) Body() ([]byte, error) {
+	return json.Marshal(u.data)
+}
+```
+
+Setup emitter
+
+```go
+config := sarama.NewConfig()
+config.Producer.Retry.Max = 5
+config.Producer.RequiredAcks = sarama.WaitForAll
+config.Producer.Return.Successes = true
+
+addresses := []string{"localhost:9092"}
+
+prd, err := sarama.NewSyncProducer(addresses, config)
+if err != nil {
+    log.Fatal(err)
+}
+defer prd.Close()
+
+event := titan.NewEmitter(prd)
+```
+
+Send event
+
+```go
+ctx := context.Background()
+userRegistered := &userRegistration{
+    Name:  "Ramadani",
+    Email: "dani@gmail.com",
+}
+
+if err = event.Emit(ctx, &userRegisteredEvent{data: userRegistered}); err != nil {
+    log.Fatal(err)
+}
+```
+
+#### Event Listener
+
+Create listeners
+
+```go
+type sendEmailVerificationListener struct{}
+
+func (l *sendEmailVerificationListener) Handle(ctx context.Context, value []byte) (err error) {
+	data := &userRegistration{}
+	_ = json.Unmarshal(value, data)
+
+	log.Println("send email verification to", data.Email)
+	return
+}
+```
+
+Listen the events
+
+```go
+saramaCog := sarama.NewConfig()
+saramaCog.Version = sarama.V0_10_2_0
+saramaCog.Consumer.Offsets.Initial = sarama.OffsetOldest
+saramaCog.Consumer.Group.Rebalance.Strategy = sarama.BalanceStrategyRoundRobin
+
+addresses := []string{"localhost:9092"}
+consumerGroup, err := sarama.NewConsumerGroup(addresses, "titan-1", saramaCog)
+if err != nil {
+    log.Panic(err)
+}
+
+ctx, cancel := context.WithCancel(context.Background())
+event := titan.DefaultConsumerGroupEventListener(consumerGroup)
+
+_ = event.On(ctx, "userRegistered", []saturn.Listener{
+    &sendEmailVerificationListener{},
+})
+
+go func() {    
+    if err = event.Listen(ctx); err != nil {
+        log.Panic(err)
+    }
+}()
+
+<-event.Ready()
+
+log.Println("Titan up and running!...")
+
+sigterm := make(chan os.Signal, 1)
+signal.Notify(sigterm, syscall.SIGINT, syscall.SIGTERM)
+select {
+case <-ctx.Done():
+    log.Println("terminating: context cancelled")
+case <-sigterm:
+    log.Println("terminating: via signal")
+}
+cancel()
+
+if err = consumerGroup.Close(); err != nil {
+    log.Panicf("Error closing consumer group: %v", err)
+}
+```