fix: quickstart wrong package when go.mod exists in parent dir (#2048)

* chore: fix typo

* fix: quickstart in dir with go.mod

* fix: runner failed

* chore: refine code

* chore: simplify quickstart mono

tools/goctl/pkg/golang/format.go

@@ -0,0 +1,12 @@
+package golang
+
+import goformat "go/format"
+
+func FormatCode(code string) string {
+	ret, err := goformat.Source([]byte(code))
+	if err != nil {
+		return code
+	}
+
+	return string(ret)
+}