Refactor docs

Author: wooorm

readme.md

@@ -64,7 +64,7 @@ internals away.
 ## 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 mdast-util-mdx
@@ -88,7 +88,7 @@ In browsers with [`esm.sh`][esmsh]:
 
 Say our document `example.mdx` contains:
 
-```markdown
+```mdx
 import Box from "place"
 
 Here’s an expression:
@@ -249,7 +249,7 @@ console.log(out)
 }
 ```
 
-```markdown
+```mdx
 import Box from "place"
 
 Here’s an expression:
@@ -376,10 +376,13 @@ visit(tree, function (node) {
 
 ## 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, `mdast-util-mdx@^2`,
+compatible with Node.js 12.
 
 This utility works with `mdast-util-from-markdown` version 1+ and
 `mdast-util-to-markdown` version 1+.
@@ -421,9 +424,9 @@ abide by its terms.
 
 [downloads]: https://www.npmjs.com/package/mdast-util-mdx
 
-[size-badge]: https://img.shields.io/bundlephobia/minzip/mdast-util-mdx.svg
+[size-badge]: https://img.shields.io/badge/dynamic/json?label=minzipped%20size&query=$.size.compressedSize&url=https://deno.bundlejs.com/?q=mdast-util-mdx
 
-[size]: https://bundlephobia.com/result?p=mdast-util-mdx
+[size]: https://bundlejs.com/?q=mdast-util-mdx
 
 [sponsors-badge]: https://opencollective.com/unified/sponsors/badge.svg