doc: update README.md

README.md

@@ -244,11 +244,7 @@ const htmlStr = unified()
 - [`rehype-video`](https://github.com/jaywcjlove/rehype-video) Add improved video syntax: links to `.mp4` and `.mov` turn into videos.
 - [`rehype-attr`](https://github.com/jaywcjlove/rehype-attr) New syntax to add attributes to Markdown.
 - [`rehype-ignore`](https://github.com/jaywcjlove/rehype-ignore) Ignore content display via HTML comments, Shown in GitHub readme, excluded in HTML.
-- [`rehypejs`](https://github.com/rehypejs/rehype) HTML processor powered by plugins part of the @unifiedjs collective
-- [`remark-parse`](https://www.npmjs.com/package/remark-parse) remark plugin to parse Markdown
-- [`remark-rehype`](https://www.npmjs.com/package/remark-rehype) remark plugin to transform to rehype
-- [`rehype-raw`](https://www.npmjs.com/package/rehype-raw) rehype plugin to reparse the tree (and raw nodes)
-- [`rehype-stringify`](https://www.npmjs.com/package/rehype-stringify) rehype plugin to serialize HTML
+- [`remark-github-blockquote-alert`](https://github.com/jaywcjlove/remark-github-blockquote-alert) Remark plugin to add support for GitHub Alert.
 
 ## Contributors