Examine source code of smooth vi

{
  "manifest_version": 3,
  "name": "smooth vi",
  "version": "1.5",
  "browser_specific_settings": {
    "gecko": {
      "id": "{aea01107-f542-40da-9c9d-9535f0b17a2c}"
    }
  },
  "description": "Simple and smooth vi mode for viewing web pages",
  "icons": {
    "48": "smooth_vi_48.png",
    "96": "smooth_vi_96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "smoothVi.js"
      ]
    }
  ],
  "permissions": [
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_icon": {
      "48": "smooth_vi_disabled_48.png",
      "96": "smooth_vi_disabled_96.png"
    }
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  }
}