message: add missing npx link
diff: @@ -81,3 +81,5 @@ example of how we're testing our components.
  - Favor extending or wrapping components for more complex operations.
  - Maintain design system consistency with utilities as props (for spacing, color, font-size, line-height, widths, and radii).
  +
  +[npx]: https://www.npmjs.com/package/npx
  