Examine source code of Vote Reminder

{
  "manifest_version": 2,
  "name": "Vote Reminder",
  "version": "1.5",
  "description": "Reçois une notification dès que tu peux voter à nouveau sur Sirius.",
  "icons": {
    "48": "icon.png",
    "128": "icon.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "permissions": [
    "tabs",
    "notifications",
    "alarms",
    "storage",
    "https://sirius-game.fr/*",
    "https://www.sirius-game.fr/*"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "128": "icon.png"
    },
    "default_title": "Vote Reminder"
  },
  "content_scripts": [
    {
      "matches": [
        "https://sirius-game.fr/vote*",
        "https://www.sirius-game.fr/vote*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "vote-reminder@orion",
      "strict_min_version": "91.0"
    }
  }
}