Drop Node < 12 support

Author: webketje

package-lock.json

@@ -55,13 +55,15 @@
     "mocha": "^9.2.1",
     "nyc": "^15.1.0",
     "prettier": "^2.5.1",
-    "release-it": "^14.12.5",
-    "rimraf": "^3.0.2"
+    "release-it": "^14.12.5"
   },
   "peerDependencies": {
     "metalsmith": "^2.3.0"
   },
   "publishConfig": {
     "access": "public"
+  },
+  "engines": {
+    "node": ">=12.0.0"
   }
 }