fix GitHub workflow badge URL

See badges/shields#8671

README.md

@@ -69,7 +69,7 @@ your logo will show up here with a link to your website. [[Become a sponsor](htt
 [license-url]: https://github.com/plouc/nivo/blob/master/LICENSE.md
 [npm-image]: https://img.shields.io/npm/v/@nivo/core.svg?style=flat-square
 [npm-url]: https://www.npmjs.com/~nivo
-[actions-image]: https://img.shields.io/github/workflow/status/plouc/nivo/CI.svg?style=flat-square
+[actions-image]: https://img.shields.io/github/actions/workflow/status/plouc/nivo/ci.yml?branch=master&style=flat-square
 [actions-url]: https://github.com/plouc/nivo/actions
 [prettier-image]: https://img.shields.io/badge/styled_with-prettier-ff69b4.svg?style=flat-square
 [prettier-url]: https://github.com/prettier/prettier