Examine source code of Spotify Light Mode

{
  "manifest_version": 2,
  "name": "Spotify Light Mode",
  "description": "Bring light mode to Spotify's web player — always on, or only when your OS is in light mode.",
  "version": "0.1.8",
  "icons": {
    "16": "icon-16.png",
    "32": "icon-32.png",
    "48": "icon-48.png",
    "96": "icon-96.png",
    "128": "icon-128.png"
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "spotify-light-mode@joaco.io",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "browser_action": {
    "default_title": "Spotify Light Mode",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://open.spotify.com/*"
      ],
      "run_at": "document_start",
      "js": [
        "content-scripts/spotify.js"
      ]
    }
  ]
}