Refactor docs

Author: wooorm

readme.md

@@ -41,7 +41,7 @@ To change heading ranks, use
 ## Install
 
 This package is [ESM only][esm].
-In Node.js (version 14.14+ and 16.0+), install with [npm][]:
+In Node.js (version 16+), install with [npm][]:
 
 ```sh
 npm install hast-util-heading-rank
@@ -73,7 +73,7 @@ headingRank(h('h5', 'Alpha')) //=> 5
 
 ## API
 
-This package exports the identifier [`headingRank`][headingrank].
+This package exports the identifier [`headingRank`][api-heading-rank].
 There is no default export.
 
 ### `headingRank(node)`
@@ -87,7 +87,7 @@ Get the rank (`1` to `6`) of headings (`h1` to `h6`).
 
 ###### Returns
 
-Rank of the heading or `undefined` if not a heading (`number | undefined`).
+Rank of the heading (`number`) or `undefined` if not a heading.
 
 ## Types
 
@@ -96,10 +96,13 @@ It exports no additional types.
 
 ## Compatibility
 
-Projects maintained by the unified collective are compatible with all maintained
+Projects maintained by the unified collective are compatible with maintained
 versions of Node.js.
-As of now, that is Node.js 14.14+ and 16.0+.
-Our projects sometimes work with older versions, but this is not guaranteed.
+
+When we cut a new major release, we drop support for unmaintained versions of
+Node.
+This means we try to keep the current release line,
+`hast-util-heading-rank@^2`, compatible with Node.js 12.
 
 ## Security
 
@@ -141,9 +144,9 @@ abide by its terms.
 
 [downloads]: https://www.npmjs.com/package/hast-util-heading-rank
 
-[size-badge]: https://img.shields.io/bundlephobia/minzip/hast-util-heading-rank.svg
+[size-badge]: https://img.shields.io/badge/dynamic/json?label=minzipped%20size&query=$.size.compressedSize&url=https://deno.bundlejs.com/?q=hast-util-heading-rank
 
-[size]: https://bundlephobia.com/result?p=hast-util-heading-rank
+[size]: https://bundlejs.com/?q=hast-util-heading-rank
 
 [sponsors-badge]: https://opencollective.com/unified/sponsors/badge.svg
 
@@ -183,4 +186,4 @@ abide by its terms.
 
 [hast-util-shift-heading]: https://github.com/syntax-tree/hast-util-shift-heading
 
-[headingrank]: #headingranknode
+[api-heading-rank]: #headingranknode