add experimental handlers examples

Former-commit-id: 8d8a0d15afce2554dc5926f6b9bd9c42cb95dad0

_examples/experimental-handlers/tollboothic/limit-handler/main.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"github.com/kataras/iris"
+
+	"github.com/didip/tollbooth"
+	"github.com/iris-contrib/middleware/tollboothic"
+)
+
+// $ go get github.com/didip/tollbooth
+// $ go run main.go
+
+func main() {
+	app := iris.New()
+
+	limiter := tollbooth.NewLimiter(1, nil)
+	//
+	// or create a limiter with expirable token buckets
+	// This setting means:
+	// create a 1 request/second limiter and
+	// every token bucket in it will expire 1 hour after it was initially set.
+	// limiter := tollbooth.NewLimiter(1, &limiter.ExpirableOptions{DefaultExpirationTTL: time.Hour})
+
+	app.Get("/", tollboothic.LimitHandler(limiter), func(ctx iris.Context) {
+		ctx.HTML("<b>Hello, world!</b>")
+	})
+
+	app.Run(iris.Addr(":8080"))
+}
+
+// Read more at: https://github.com/didip/tollbooth