Add improved docs

Author: wooorm

readme.md

@@ -8,33 +8,72 @@
 [![Backers][backers-badge]][collective]
 [![Chat][chat-badge]][chat]
 
-Extension for [`mdast-util-from-markdown`][from-markdown] and/or
-[`mdast-util-to-markdown`][to-markdown] to support GitHub flavored markdown
-task list items in **[mdast][]**.
-When parsing (`from-markdown`), must be combined with
-[`micromark-extension-gfm-task-list-item`][extension].
+[mdast][] extensions to parse and serialize [GFM][] task list items.
+
+## Contents
+
+*   [What is this?](#what-is-this)
+*   [When to use this](#when-to-use-this)
+*   [Install](#install)
+*   [Use](#use)
+*   [API](#api)
+    *   [`gfmTaskListItemFromMarkdown`](#gfmtasklistitemfrommarkdown)
+    *   [`gfmTaskListItemToMarkdown`](#gfmtasklistitemtomarkdown)
+*   [Syntax tree](#syntax-tree)
+    *   [Nodes](#nodes)
+    *   [Content model](#content-model)
+*   [Types](#types)
+*   [Compatibility](#compatibility)
+*   [Related](#related)
+*   [Contribute](#contribute)
+*   [License](#license)
+
+## What is this?
+
+This package contains extensions that add support for the task list item syntax
+enabled by GFM to [`mdast-util-from-markdown`][mdast-util-from-markdown] and
+[`mdast-util-to-markdown`][mdast-util-to-markdown].
 
 ## When to use this
 
-Use this if you’re dealing with the AST manually.
-It’s might be better to use [`remark-gfm`][remark-gfm] with **[remark][]**,
-which includes this but provides a nicer interface and makes it easier to
-combine with hundreds of plugins.
+These tools are all rather low-level.
+In most cases, you’d want to use [`remark-gfm`][remark-gfm] with remark instead.
 
-## Install
+When you are working with syntax trees and want all of GFM, use
+[`mdast-util-gfm`][mdast-util-gfm] instead.
+
+When working with `mdast-util-from-markdown`, you must combine this package with
+[`micromark-extension-gfm-task-list-item`][extension].
+
+This utility does not handle how markdown is turned to HTML.
+That’s done by [`mdast-util-to-hast`][mdast-util-to-hast].
 
-This package is [ESM only](https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c):
-Node 12+ is needed to use it and it must be `import`ed instead of `require`d.
+## Install
 
-[npm][]:
+This package is [ESM only][esm].
+In Node.js (version 12.20+, 14.14+, or 16.0+), install with [npm][]:
 
 ```sh
 npm install mdast-util-gfm-task-list-item
 ```
 
+In Deno with [`esm.sh`][esmsh]:
+
+```js
+import {gfmTaskListItemFromMarkdown, gfmTaskListItemToMarkdown} from 'https://esm.sh/mdast-util-gfm-task-list-item@1'
+```
+
+In browsers with [`esm.sh`][esmsh]:
+
+```html
+<script type="module">
+  import {gfmTaskListItemFromMarkdown, gfmTaskListItemToMarkdown} from 'https://esm.sh/mdast-util-gfm-task-list-item@1?bundle'
+</script>
+```
+
 ## Use
 
-Say we have the following file, `example.md`:
+Say our document `example.md` contains:
 
 ```markdown
 * [ ] To do
@@ -44,16 +83,16 @@ Say we have the following file, `example.md`:
 2. [x] …messages
 ```
 
-And our module, `example.js`, looks as follows:
+…and our module `example.js` looks as follows:
 
 ```js
-import fs from 'node:fs'
+import fs from 'node:fs/promises'
 import {fromMarkdown} from 'mdast-util-from-markdown'
 import {toMarkdown} from 'mdast-util-to-markdown'
 import {gfmTaskListItem} from 'micromark-extension-gfm-task-list-item'
 import {gfmTaskListItemFromMarkdown, gfmTaskListItemToMarkdown} from 'mdast-util-gfm-task-list-item'
 
-const doc = fs.readFileSync('example.md')
+const doc = await fs.readFile('example.md')
 
 const tree = fromMarkdown(doc, {
   extensions: [gfmTaskListItem],
@@ -67,8 +106,7 @@ const out = toMarkdown(tree, {extensions: [gfmTaskListItemToMarkdown]})
 console.log(out)
 ```
 
-Now, running `node example` yields (positional info removed for the sake of
-brevity):
+…now running `node example.js` yields (positional info removed for brevity):
 
 ```js
 {
@@ -136,38 +174,75 @@ brevity):
 
 ## API
 
-This package exports the following identifier: `gfmTaskListItemFromMarkdown`,
+This package exports the identifiers `gfmTaskListItemFromMarkdown` and
 `gfmTaskListItemToMarkdown`.
 There is no default export.
 
 ### `gfmTaskListItemFromMarkdown`
 
+Extension for [`mdast-util-from-markdown`][mdast-util-from-markdown].
+
 ### `gfmTaskListItemToMarkdown`
 
-Support task list items.
-The exports are extensions, respectively
-for [`mdast-util-from-markdown`][from-markdown] and
-[`mdast-util-to-markdown`][to-markdown].
+Extension for [`mdast-util-to-markdown`][mdast-util-to-markdown].
+
+## Syntax tree
+
+The following interfaces are added to **[mdast][]** by this utility.
+
+### Nodes
+
+#### `ListItem` (GFM)
+
+```idl
+interface ListItemGfm <: ListItem {
+  checked: boolean?
+}
+```
+
+In GFM, a `checked` field can be present.
+It represents whether the item is done (when `true`), not done (when `false`),
+or indeterminate or not applicable (when `null` or not present).
+
+### Content model
+
+#### `ListContent` (GFM)
+
+```idl
+type ListContentGfm = ListItemGfm
+```
+
+## Types
+
+This package is fully typed with [TypeScript][].
+It does not export additional types.
+
+The `ListItemGfm` node type is supported in `@types/mdast` by default.
+
+## Compatibility
+
+Projects maintained by the unified collective are compatible with all maintained
+versions of Node.js.
+As of now, that is Node.js 12.20+, 14.14+, and 16.0+.
+Our projects sometimes work with older versions, but this is not guaranteed.
+
+This plugin works with `mdast-util-from-markdown` version 1+ and
+`mdast-util-to-markdown` version 1+.
 
 ## Related
 
-*   [`remarkjs/remark`][remark]
-    — markdown processor powered by plugins
 *   [`remarkjs/remark-gfm`][remark-gfm]
     — remark plugin to support GFM
-*   [`micromark/micromark`][micromark]
-    — the smallest commonmark-compliant markdown parser that exists
+*   [`syntax-tree/mdast-util-gfm`][mdast-util-gfm]
+    — same but all of GFM (autolink literals, footnotes, strikethrough, tables,
+    tasklists)
 *   [`micromark/micromark-extension-gfm-task-list-item`][extension]
     — micromark extension to parse GFM task list items
-*   [`syntax-tree/mdast-util-from-markdown`][from-markdown]
-    — mdast parser using `micromark` to create mdast from markdown
-*   [`syntax-tree/mdast-util-to-markdown`][to-markdown]
-    — mdast serializer to create markdown from mdast
 
 ## Contribute
 
-See [`contributing.md` in `syntax-tree/.github`][contributing] for ways to get
-started.
+See [`contributing.md`][contributing] in [`syntax-tree/.github`][health] for
+ways to get started.
 See [`support.md`][support] for ways to get help.
 
 This project has a [code of conduct][coc].
@@ -208,10 +283,18 @@ abide by its terms.
 
 [npm]: https://docs.npmjs.com/cli/install
 
+[esm]: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c
+
+[esmsh]: https://esm.sh
+
+[typescript]: https://www.typescriptlang.org
+
 [license]: license
 
 [author]: https://wooorm.com
 
+[health]: https://github.com/syntax-tree/.github
+
 [contributing]: https://github.com/syntax-tree/.github/blob/HEAD/contributing.md
 
 [support]: https://github.com/syntax-tree/.github/blob/HEAD/support.md
@@ -220,14 +303,16 @@ abide by its terms.
 
 [mdast]: https://github.com/syntax-tree/mdast
 
-[remark]: https://github.com/remarkjs/remark
-
 [remark-gfm]: https://github.com/remarkjs/remark-gfm
 
-[from-markdown]: https://github.com/syntax-tree/mdast-util-from-markdown
+[mdast-util-from-markdown]: https://github.com/syntax-tree/mdast-util-from-markdown
 
-[to-markdown]: https://github.com/syntax-tree/mdast-util-to-markdown
+[mdast-util-to-markdown]: https://github.com/syntax-tree/mdast-util-to-markdown
 
-[micromark]: https://github.com/micromark/micromark
+[mdast-util-gfm]: https://github.com/syntax-tree/mdast-util-gfm
+
+[mdast-util-to-hast]: https://github.com/syntax-tree/mdast-util-to-hast
 
 [extension]: https://github.com/micromark/micromark-extension-gfm-task-list-item
+
+[gfm]: https://github.github.com/gfm/