Examine source code of GnuPG Decryptor

{
  "manifest_version": 2,
  "name": "GnuPG Decryptor",
  "version": "1.1",
  "description": "GnuPG_Decryptor is a browser extension that detects and decrypts encrypted elements on a web page using gpg application.",
  "icons": {
    "16": "/icons/gnupg_16.png",
    "32": "/icons/gnupg_32.png",
    "48": "/icons/gnupg_48.png",
    "64": "/icons/gnupg_64.png",
    "96": "/icons/gnupg_96.png",
    "128": "/icons/gnupg_128.png",
    "256": "/icons/gnupg_256.png"
  },
  "permissions": [
    "nativeMessaging",
    "storage"
  ],
  "background": {
    "scripts": [
      "/src/js/background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "16": "/icons/gnupg_16.png",
      "32": "/icons/gnupg_32.png",
      "48": "/icons/gnupg_48.png",
      "64": "/icons/gnupg_64.png",
      "96": "/icons/gnupg_96.png",
      "128": "/icons/gnupg_128.png",
      "256": "/icons/gnupg_256.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "/src/js/gnupg_decryptor.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "GnuPG_Decryptor@fit.vutbr.cz",
      "strict_min_version": "55.0"
    }
  }
}