Fix issues with last version of Electron in 2023

[Baxi19]

🔨 Updating project to fix some issues in 2023 🔥

🛠️ This pull request will fix the issues 🐛 of the project to keep using as a template in 2023 ⭐

The changes are 🪅 :

• Update electron version: 23.1.1 :octocat:
• Fix the issue with required in rendered.js 💯
• Add web preferences in main.js 🌎
• Update script's syntax in index.html 🗒️

🇨🇷 I hope this fix helps more people to implement FCM with Electron 💣 🔥