Examine source code of dol2eur

{
  "manifest_version": 2,
  "name": "dol2eur",
  "version": "1.1.0",
  "description": "Convertit les prix en devises vers euro",
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "dol2eur@julien.local",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_action": {
    "default_title": "Convertir vers euro",
    "default_icon": "icons/icon48.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}