build: run build on npm publish

Author: jccr

package.json

@@ -18,7 +18,8 @@
   },
   "scripts": {
     "build": "rollup -c",
-    "test": "node --experimental-modules node_modules/.bin/c8 --reporter=html --reporter=text --check-coverage node --experimental-modules node_modules/.bin/mocha"
+    "test": "node --experimental-modules node_modules/.bin/c8 --reporter=html --reporter=text --check-coverage node --experimental-modules node_modules/.bin/mocha",
+    "prepublishOnly": "npm run build"
   },
   "repository": {
     "type": "git",