Fix typos

Author: wooorm

readme.md

@@ -161,17 +161,17 @@ Take a look at [`lib/handle`][handlers] for examples.
 ## List of extensions
 
 *   [`syntax-tree/mdast-util-frontmatter`](https://github.com/syntax-tree/mdast-util-frontmatter)
-    — parse frontmatter (YAML, TOML, more)
+    — serialize frontmatter (YAML, TOML, more)
 *   [`syntax-tree/mdast-util-gfm`](https://github.com/syntax-tree/mdast-util-gfm)
-    — parse GFM
+    — serialize GFM
 *   [`syntax-tree/mdast-util-gfm-autolink-literal`](https://github.com/syntax-tree/mdast-util-gfm-autolink-literal)
-    — parse GFM autolink literals
+    — serialize GFM autolink literals
 *   [`syntax-tree/mdast-util-gfm-strikethrough`](https://github.com/syntax-tree/mdast-util-gfm-strikethrough)
-    — parse GFM strikethrough
+    — serialize GFM strikethrough
 *   [`syntax-tree/mdast-util-gfm-table`](https://github.com/syntax-tree/mdast-util-gfm-table)
-    — parse GFM tables
+    — serialize GFM tables
 *   [`syntax-tree/mdast-util-gfm-task-list-item`](https://github.com/syntax-tree/mdast-util-gfm-task-list-item)
-    — parse GFM task list items
+    — serialize GFM task list items
 
 ## Security