message: docs: add more CDN services link
diff: @@ -44,6 +44,12 @@ The easiest way to use Vant is to include a CDN link in the html file, after whi
  </script>
  ```
  +You can use Vant through these free CDN services:
  +
  +- [jsdelivr](https://www.jsdelivr.com/package/npm/vant)
  +- [cdnjs](https://cdnjs.com/libraries/vant)
  +- [unpkg](https://unpkg.com/)
  +
  ### CLI
  We recommend to use [Vue Cli](https://cli.vuejs.org/) to create a new project.
  