Examine source code of Vorfreude

{
  "name": "Vorfreude",
  "description": "When you can't wait but have to",
  "version": "0.4.6",
  "manifest_version": 2,
  "browser_action": {
    "default_title": "vorfreude",
    "default_icon": {
      "32": "images/icon32.png"
    }
  },
  "icons": {
    "128": "images/icon128.png"
  },
  "options_ui": {
    "page": "settings.html",
    "open_in_tab": true
  },
  "content_security_policy": "object-src 'self'; script-src 'self' 'sha256-6b7Hu5jX9wMdcwZnkWBaMem1YaFeXzlqjsJMxYHZAbw=' 'sha256-UxL0fgqswYhUasYURTPp+yvr8dN6XQaop5BFQOmnedo='",
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "storage",
    "unlimitedStorage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{66dbbcff-1638-4df9-8090-c00c330a2ef2}"
    }
  }
}