Refactor to use @imports

Author: wooorm

lib/index.js

@@ -1,7 +1,7 @@
 /**
- * @typedef {import('mdast-util-from-markdown').Extension} FromMarkdownExtension
- * @typedef {import('mdast-util-gfm').Options} Options
- * @typedef {import('mdast-util-to-markdown').Options} ToMarkdownExtension
+ * @import {Extension as FromMarkdownExtension} from 'mdast-util-from-markdown'
+ * @import {Options} from 'mdast-util-gfm'
+ * @import {Options as ToMarkdownExtension} from 'mdast-util-to-markdown'
  */
 
 import {