Examine source code of Invidiousify

{
  "manifest_version": 2,
  "name": "Invidiousify",
  "version": "1.0",
  "description": "Replace youtube embeds with invidious embeds",
  "icons": {
    "48": "img/invidious.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "invidiousify.js"
      ]
    }
  ],
  "options_ui": {
    "page": "settings/settings.html"
  },
  "permissions": [
    "storage",
    "https://api.invidious.io/instances.json"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{fe147a0d-c8dc-425e-9e94-ad60a888cfd5}"
    }
  }
}