Examine source code of Marca RSS for Firefox

{
  "version": "1.2.0",
  "name": "__MSG_appName__",
  "short_name": "__MSG_shortName__",
  "description": "__MSG_appDesc__",
  "default_locale": "es",
  "permissions": [
    "storage",
    "alarms",
    "https://news.zamok.cloud/api/marca"
  ],
  "background": {
    "scripts": [
      "dayjs/index.js",
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "16": "img/icon_16.png",
      "48": "img/icon_48.png",
      "128": "img/icon_128.png"
    },
    "default_title": "__MSG_appName__",
    "default_popup": "popup/popup.html"
  },
  "icons": {
    "16": "img/icon_16.png",
    "48": "img/icon_48.png",
    "128": "img/icon_128.png"
  },
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{acbb5838-6bcc-4d09-9e11-fa0be1bf620f}"
    }
  }
}