add http timeout example

_examples/http-server/timeout/main.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"context"
+	"time"
+
+	"github.com/kataras/iris/v12"
+)
+
+func main() {
+	app := iris.New()
+
+	app.Get("/test", func(ctx iris.Context) {
+		w := new(worker)
+		result := w.Work(ctx)
+		ctx.WriteString(result)
+	})
+
+	app.Listen(":8080", iris.WithTimeout(4*time.Second))
+}
+
+type worker struct{}
+
+func (w *worker) Work(ctx context.Context) string {
+	t := time.Tick(time.Second)
+	times := 0
+	for {
+		select {
+		case <-ctx.Done():
+			println("context.Done: canceled")
+			return "Work canceled"
+		case <-t:
+			times++
+			println("Doing some work...")
+
+			if times > 5 {
+				return "Work is done with success"
+			}
+		}
+	}
+
+	return "nothing to do here"
+}