Add better docs

Author: wooorm

readme.md

@@ -13,8 +13,12 @@ Extension for [`mdast-util-from-markdown`][from-markdown] and/or
 When parsing (`from-markdown`), must be combined with
 [`micromark-extension-frontmatter`][extension].
 
-You probably shouldn’t use this package directly, but instead use
-[`remark-frontmatter`][remark-frontmatter] with **[remark][]**.
+## When to use this
+
+Use this if you’re dealing with the AST manually.
+It’s probably nicer to use [`remark-frontmatter`][remark-frontmatter] with
+**[remark][]**, which includes this but provides a nicer interface and
+makes it easier to combine with hundreds of plugins.
 
 ## Install
 
@@ -39,25 +43,25 @@ title = "New Website"
 # Other markdown
 ```
 
-And our script, `example.js`, looks as follows:
+And our module, `example.js`, looks as follows:
 
 ```js
-var fs = require('fs')
-var fromMarkdown = require('mdast-util-from-markdown')
-var toMarkdown = require('mdast-util-to-markdown')
-var syntax = require('micromark-extension-frontmatter')
-var frontmatter = require('mdast-util-frontmatter')
+import fs from 'node:fs'
+import {fromMarkdown} from 'mdast-util-from-markdown'
+import {toMarkdown} from 'mdast-util-to-markdown'
+import {frontmatter} from 'micromark-extension-frontmatter'
+import {frontmatterFromMarkdown, frontmatterToMarkdown} from 'mdast-util-frontmatter'
 
-var doc = fs.readFileSync('example.md')
+const doc = fs.readFileSync('example.md')
 
-var tree = fromMarkdown(doc, {
-  extensions: [syntax(['yaml', 'toml'])],
-  mdastExtensions: [frontmatter.fromMarkdown(['yaml', 'toml'])]
+const tree = fromMarkdown(doc, {
+  extensions: [frontmatter(['yaml', 'toml'])],
+  mdastExtensions: [frontmatterFromMarkdown(['yaml', 'toml'])]
 })
 
 console.log(tree)
 
-var out = toMarkdown(tree, {extensions: [frontmatter.toMarkdown(['yaml', 'toml'])]})
+const out = toMarkdown(tree, {extensions: [frontmatterToMarkdown(['yaml', 'toml'])]})
 
 console.log(out)
 ```