chore: adds the "engines.node" option

package.json

@@ -9,6 +9,9 @@
     "import": "./src/index.js",
     "require": "./dist/cjs/index.cjs"
   },
+  "engines": {
+    "node": ">=12"
+  },
   "scripts": {
     "lint": "tsc && eslint .",
     "lint:fix": "tsc && eslint . --fix",