chore: add npm build script

Author: jamesgeorge007

package-lock.json

@@ -6,9 +6,14 @@
   "keywords": [],
   "author": "James George",
   "license": "MIT",
+  "scripts": {
+    "build": "ncc build index.js -o dist"
+  },
   "dependencies": {
     "@actions/core": "^1.2.4",
     "actions-toolkit": "^5.0.0"
   },
-  "devDependencies": {}
+  "devDependencies": {
+    "@zeit/ncc": "^0.22.3"
+  }
 }