chore: Add clean and prepub scripts

Author: dennib

package.json

@@ -8,6 +8,8 @@
   "files": ["dist"],
   "scripts": {
     "build": "rollup -c",
+    "clean": "rm -rf dist",
+    "prepub": "npm-run-all clean build",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "repository": {