message: fix: amend InitializeColorMode steps for Next.js
  See for further guidelines on customising the `_document`.
diff: @@ -270,7 +270,7 @@ const theme = {
  Here's how to add it for Next.js:
  ```jsx live=false
  -// pages/_app.js
  +// pages/_document.js
  import { InitializeColorMode } from "@chakra-ui/core"
  export default class Document extends NextDocument {
  