chore: add more example (#5)

* chore: add more example

* chore: add example with different resp type

* remove error

example/http/http.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"github.com/hoanguyenkh/promise4g"
+	"time"
+)
+
+type httpResponse1 struct {
+	Message   string `json:"message"`
+	RequestId string `json:"requestId"`
+}
+
+type httpResponse2 struct {
+	Username  string `json:"username"`
+	RequestId string `json:"requestId"`
+}
+
+func fakeHttp1(url string) (httpResponse1, error) {
+	fmt.Println("fakeHttp1", url)
+	time.Sleep(100 * time.Millisecond)
+	return httpResponse1{
+		Message:   "hello world",
+		RequestId: "requestId 1",
+	}, nil
+}
+
+func fakeHttp2(url string) (httpResponse2, error) {
+	fmt.Println("fakeHttp2", url)
+	time.Sleep(200 * time.Millisecond)
+	return httpResponse2{
+		Username:  "username",
+		RequestId: "requestId 2",
+	}, nil
+}
+
+func main() {
+	ctx := context.Background()
+	p1 := promise4g.New(ctx, func(resolve func(any), reject func(error)) {
+		resp1, err := fakeHttp1("fakeHttp1")
+		if err != nil {
+			reject(err)
+		} else {
+			resolve(resp1)
+		}
+	})
+
+	p2 := promise4g.New(ctx, func(resolve func(any), reject func(error)) {
+		resp1, err := fakeHttp2("fakeHttp2")
+		if err != nil {
+			reject(err)
+		} else {
+			resolve(resp1)
+		}
+	})
+
+	p := promise4g.All(ctx, p1, p2)
+	results, err := p.Await(ctx)
+	if err != nil {
+		panic(err)
+	}
+
+	res1 := results[0].(httpResponse1)
+	res2 := results[1].(httpResponse2)
+	fmt.Println(res1.RequestId, res1.Message)
+	fmt.Println(res2.RequestId, res2.Username)
+}