Examine source code of CAT4Web

{
  "manifest_version": 3,
  "name": "CAT4Web",
  "description": "CAT4Web - CAT features on the Web!",
  "version": "0.4.0",
  "browser_specific_settings": {
    "gecko": {
      "id": "{0d719781-f837-434f-b79c-bd310cb2e393}",
      "strict_min_version": "128.0"
    }
  },
  "icons": {
    "16": "icon16.png",
    "32": "icon32.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "background": {
    "scripts": [
      "background-firefox.js"
    ]
  },
  "host_permissions": [
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "run_at": "document_idle",
      "js": [
        "cat4web.min.js",
        "catSync.js"
      ],
      "world": "MAIN"
    }
  ],
  "action": {
    "default_title": "CAT4Web",
    "default_icon": {
      "16": "icon16.png",
      "32": "icon32.png",
      "48": "icon48.png"
    }
  }
}