Examine source code of Last.fm Theme Customizer

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "description": "__MSG_extText__",
  "version": "1.6.1",
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://www.last.fm/*"
      ],
      "js": [
        "lastfm.ts"
      ],
      "run_at": "document_end"
    }
  ],
  "icons": {
    "48": "img/icon-64.png",
    "96": "img/icon-128.png"
  },
  "options_ui": {
    "page": "options.html"
  },
  "background": {
    "scripts": [
      "background.ts"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{478caa20-1bec-466f-848a-34044576f517}"
    }
  }
}