Include product_info.js (renamed) in built add-on.

src/manifest.json

@@ -23,7 +23,7 @@
   "content_scripts": [
     {
       "matches": ["<all_urls>"],
-      "js": ["productInfo.js"]
+      "js": ["product_info.js"]
     }
   ],
   "sidebar_action": {

webpack.config.js

@@ -19,6 +19,8 @@ module.exports = {
   },
   plugins: [
     new CopyWebpackPlugin([
+      {from: 'product_info.js'},
+
       // Static files
       {from: '**/*.svg'},
       {from: '**/*.html'},