feat: init update

hello/hello.go

@@ -0,0 +1,9 @@
+package hello
+
+import (
+	"net/http"
+)
+
+func HelloHandler(w http.ResponseWriter, r *http.Request) {
+	w.Write([]byte("Hello, World!"))
+}

hello/hello_test.go

@@ -0,0 +1,16 @@
+package hello
+
+import (
+	"testing"
+	"net/http/httptest"
+)
+
+func TestHelloHandler(t *testing.T) {
+	w := httptest.NewRecorder()
+	req := httptest.NewRequest("GET", "/hello", nil)
+	HelloHandler(w, req)
+	expected := "Hello, World!"
+	if w.Body.String() != expected {
+		t.Errorf("Expected %q but got %q", expected, w.Body.String())
+	}
+}