Install execa

package.json

@@ -12,7 +12,7 @@
     "lint": "eslint -c .eslintrc.js --ext .ts src",
     "build": "npm run webpack && npm run fix-types",
     "webpack": "rimraf ./build && webpack --config ./webpack.config.ts",
-    "demo": "npm run build && npm run ts-node --skip-project ./demo",
+    "demo": "ts-node --esm --skip-project ./demo/index.ts",
     "typedoc": "rimraf ./build && typedoc src/index.ts --tsconfig tsconfig.typedoc.json",
     "style": "prettier -l \"{src,scripts,demo}/**/*.{ts,html}\"",
     "style.fix": "npm run style -- --write",
@@ -84,6 +84,7 @@
     "eslint-plugin-no-null": "^1.0.2",
     "eslint-plugin-prefer-arrow": "^1.2.3",
     "eslint-plugin-unicorn": "^46.0.0",
+    "execa": "^7.1.1",
     "glob": "^9.3.0",
     "jszip": "^3.1.5",
     "mocha": "^10.0.0",