Examine source code of Live Theme for Deezer

{
  "manifest_version": 3,
  "name": "Live Theme for Deezer",
  "version": "1.0",
  "description": "Applies dynamic accent colors to Deezer based on the currently playing track",
  "browser_specific_settings": {
    "gecko": {
      "id": "liveThemeDeezer@n"
    }
  },
  "icons": {
    "240": "icons/icon240.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.deezer.com/*"
      ],
      "js": [
        "libs/vibrant.min.js",
        "content.js"
      ]
    }
  ],
  "host_permissions": [
    "*://*.dzcdn.net/*"
  ]
}