fix(gatsby-source-shopify): fix linting (#31291)

Author: wardpeet

packages/gatsby-source-shopify/README.md

@@ -1,9 +1,10 @@
 # 📣 Looking for the latest version of `gatsby-source-shopify`?
 
-👉  Get started at [`gatsbyjs/gatsby-source-shopify`](https://github.com/gatsbyjs/gatsby-source-shopify)
-* Support for incremental builds
-* Scale up to 10k products
-* Up to 16x faster builds
+👉 Get started at [`gatsbyjs/gatsby-source-shopify`](https://github.com/gatsbyjs/gatsby-source-shopify)
+
+- Support for incremental builds
+- Scale up to 10k products
+- Up to 16x faster builds
 
 `gatsbyjs/gatsby-source-shopify` will replace the below package with the next minor release of `gatsbyjs/gatsby`.