Refactor docs

Author: wooorm

readme.md

@@ -37,7 +37,7 @@ You can use [`unist-util-visit`][unist-util-visit] yourself as well.
 ## 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 unist-util-size
@@ -91,7 +91,7 @@ Calculate the number of nodes in `tree`.
 
 *   `tree`  ([`Node`][node])
     — tree to traverse
-*   `test`  ([`Test`][test])
+*   `test`  ([`Test`][test], optional)
     — `unist-util-is` compatible test (such as a node type)
 
 ###### Returns
@@ -105,10 +105,13 @@ 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, `unist-util-size@^3`,
+compatible with Node.js 12.
 
 ## Related
 
@@ -143,9 +146,9 @@ abide by its terms.
 
 [downloads]: https://www.npmjs.com/package/unist-util-size
 
-[size-badge]: https://img.shields.io/bundlephobia/minzip/unist-util-size.svg
+[size-badge]: https://img.shields.io/badge/dynamic/json?label=minzipped%20size&query=$.size.compressedSize&url=https://deno.bundlejs.com/?q=unist-util-size
 
-[size]: https://bundlephobia.com/result?p=unist-util-size
+[size]: https://bundlejs.com/?q=unist-util-size
 
 [sponsors-badge]: https://opencollective.com/unified/sponsors/badge.svg