Examine source code of Underbite

{
  "manifest_version": 2,
  "name": "Underbite",
  "version": "0.2.3",
  "description": "A more modern interface for OverbiteWX.",
  "icons": {
    "16": "/logo.svg",
    "24": "/logo.svg",
    "32": "/logo.svg",
    "48": "/logo.svg",
    "64": "/logo.svg",
    "96": "/logo.svg"
  },
  "content_scripts": [
    {
      "all_frames": true,
      "matches": [
        "https://gopher.floodgap.com/gopher/gw.lite*"
      ],
      "run_at": "document_start",
      "js": [
        "gateway.js"
      ],
      "css": [
        "gateway.css"
      ]
    }
  ],
  "background": {
    "scripts": [
      "bookmarks.js"
    ],
    "persistent": false
  },
  "permissions": [
    "bookmarks",
    "history",
    "storage"
  ],
  "protocol_handlers": [
    {
      "protocol": "gopher",
      "name": "Underbite",
      "uriTemplate": "gopher.html?%s"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{6a36d5f6-e64f-4644-ae43-567ce61447d0}"
    }
  }
}