improve package goai; add example for array items response definition

example/httpserver/response_with_json_array/controller.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"context"
+
+	"github.com/gogf/gf/v2/frame/g"
+)
+
+type Req struct {
+	g.Meta `path:"/user" method:"get"`
+}
+type Res []Item
+
+type Item struct {
+	Id   int64
+	Name string
+}
+
+var (
+	User = cUser{}
+)
+
+type cUser struct{}
+
+func (c *cUser) GetList(ctx context.Context, req *Req) (res *Res, err error) {
+	res = &Res{
+		{Id: 1, Name: "john"},
+		{Id: 2, Name: "smith"},
+		{Id: 3, Name: "alice"},
+		{Id: 4, Name: "katyusha"},
+	}
+	return
+}