add bind checkboxes example

_examples/request-body/read-form/checkboxes/main.go

@@ -0,0 +1,32 @@
+package main
+
+import "github.com/kataras/iris/v12"
+
+func main() {
+	app := iris.New()
+	app.RegisterView(iris.HTML("./templates", ".html"))
+
+	app.Get("/", showForm)
+	app.Post("/", handleForm)
+
+	app.Listen(":8080")
+}
+
+func showForm(ctx iris.Context) {
+	ctx.View("form.html")
+}
+
+type formExample struct {
+	Colors []string `form:"colors[]"` // or just colors, it'll work as expected.
+}
+
+func handleForm(ctx iris.Context) {
+	var form formExample
+	err := ctx.ReadForm(&form)
+	if err != nil {
+		ctx.StopWithError(iris.StatusBadRequest, err)
+		return
+	}
+
+	ctx.JSON(iris.Map{"Colors": form.Colors})
+}