Change to require Node.js 16

Author: wooorm

readme.md

@@ -602,8 +602,8 @@ versions of Node.js.
 
 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-to-markdown@^1`,
-compatible with Node.js 12.
+This means we try to keep the current release line, `mdast-util-to-markdown@^2`,
+compatible with Node.js 16.
 
 ## Security
 

tsconfig.json

@@ -5,10 +5,10 @@
     "declaration": true,
     "emitDeclarationOnly": true,
     "exactOptionalPropertyTypes": true,
-    "lib": ["es2020"],
+    "lib": ["es2022"],
     "module": "node16",
     "strict": true,
-    "target": "es2020"
+    "target": "es2022"
   },
   "exclude": ["coverage/", "node_modules/"],
   "include": ["**/*.js", "index.d.ts"]