Updated webpack config to inject hash in production && optimized html

[RenaudRohlinger]

Hello !

I needed to add a hash on my js files to force the cache to be updated in my game in production so I wanted to share this config with you guys.

I didn't changed the way this bootstrap project works.

• Npm run dev will generate an index.html file at the base folder with ./dist/bundle.vendor.js && ./dist/bundle.js
• Npm run deploy will generate an index.html file minified at the base folder with ./dist/bundle.vendor.js?[hash] && ./dist/bundle.js?[hash]

If the modifications are wrong with how this repo works just inform me and I'll change it.

Soon I'll add a config to optimized assets if you think this kind of config are useful, otherwise just close this pull request.

[lean]

Thanks you @RenaudROHLINGER. You did a great contribution!