Examine source code of Manga Reader

{
  "manifest_version": 2,
  "name": "Manga Reader",
  "version": "5.0.2",
  "description": "This is the deprecated manga reader for Firefox.",
  "icons": {
    "512": "/icon.png"
  },
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "512": "/icon.svg"
    },
    "default_title": "Manga Reader",
    "default_popup": "./index.html"
  },
  "permissions": [
    "clipboardWrite",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{68f502b7-1d5f-46d3-9f23-097c02731db2}"
    }
  }
}