Change master in links to HEAD

Author: wooorm

readme.md

@@ -63,21 +63,21 @@ for [cross-site scripting (XSS)][xss] attacks.
  — check if a node is a (certain) element
 * [`hast-util-has-property`](https://github.com/syntax-tree/hast-util-has-property)
  — check if a node has a property
-* [`hast-util-is-body-ok-link`](https://github.com/rehypejs/rehype-minify/tree/master/packages/hast-util-is-body-ok-link)
+* [`hast-util-is-body-ok-link`](https://github.com/rehypejs/rehype-minify/tree/HEAD/packages/hast-util-is-body-ok-link)
  — check if a node is “Body OK” link element
-* [`hast-util-is-conditional-comment`](https://github.com/rehypejs/rehype-minify/tree/master/packages/hast-util-is-conditional-comment)
+* [`hast-util-is-conditional-comment`](https://github.com/rehypejs/rehype-minify/tree/HEAD/packages/hast-util-is-conditional-comment)
  — check if a node is a conditional comment
-* [`hast-util-is-css-link`](https://github.com/rehypejs/rehype-minify/tree/master/packages/hast-util-is-css-link)
+* [`hast-util-is-css-link`](https://github.com/rehypejs/rehype-minify/tree/HEAD/packages/hast-util-is-css-link)
  — check if a node is a CSS link element
-* [`hast-util-is-css-style`](https://github.com/rehypejs/rehype-minify/tree/master/packages/hast-util-is-css-style)
+* [`hast-util-is-css-style`](https://github.com/rehypejs/rehype-minify/tree/HEAD/packages/hast-util-is-css-style)
  — check if a node is a CSS style element
 * [`hast-util-embedded`](https://github.com/syntax-tree/hast-util-embedded)
  — check if a node is an embedded element
 * [`hast-util-heading`](https://github.com/syntax-tree/hast-util-heading)
  — check if a node is a heading element
 * [`hast-util-interactive`](https://github.com/syntax-tree/hast-util-interactive)
  — check if a node is interactive
-* [`hast-util-is-javascript`](https://github.com/rehypejs/rehype-minify/tree/master/packages/hast-util-is-javascript)
+* [`hast-util-is-javascript`](https://github.com/rehypejs/rehype-minify/tree/HEAD/packages/hast-util-is-javascript)
  — check if a node is a JavaScript script element
 * [`hast-util-phrasing`](https://github.com/syntax-tree/hast-util-phrasing)
  — check if a node is phrasing content
@@ -138,11 +138,11 @@ abide by its terms.
 
 [author]: https://wooorm.com
 
-[contributing]: https://github.com/syntax-tree/.github/blob/master/contributing.md
+[contributing]: https://github.com/syntax-tree/.github/blob/HEAD/contributing.md
 
-[support]: https://github.com/syntax-tree/.github/blob/master/support.md
+[support]: https://github.com/syntax-tree/.github/blob/HEAD/support.md
 
-[coc]: https://github.com/syntax-tree/.github/blob/master/code-of-conduct.md
+[coc]: https://github.com/syntax-tree/.github/blob/HEAD/code-of-conduct.md
 
 [spec]: https://html.spec.whatwg.org/#category-label