build: run build before npm publish

Author: mauriciopoppe

package.json

@@ -15,6 +15,7 @@
   "scripts": {
     "deploy": "gh-pages-deploy",
     "html": "node site.js",
+    "prepare": "npm run build",
     "build": "npx rimraf dist && npm run html && npm run docs && npm run build:types && npm run build:webpack && npm run build:site",
     "build:webpack": "NODE_ENV=production webpack",
     "build:types": "tsc",