examples: fix dir structure (#768)

* fix dir structure

examples/http/gin/main.go

@@ -0,0 +1,28 @@
+package main
+
+import (
+	"log"
+
+	"github.com/gin-gonic/gin"
+	"github.com/go-kratos/kratos/v2"
+	"github.com/go-kratos/kratos/v2/transport/http"
+)
+
+func main() {
+	router := gin.Default()
+	router.GET("/home", func(ctx *gin.Context) {
+		ctx.String(200, "Hello Gin!")
+	})
+	httpSrv := http.NewServer(http.Address(":8000"))
+	httpSrv.HandlePrefix("/", router)
+
+	app := kratos.New(
+		kratos.Name("gin"),
+		kratos.Server(
+			httpSrv,
+		),
+	)
+	if err := app.Run(); err != nil {
+		log.Println(err)
+	}
+}