Examine source code of CaelestiaSites

{
  "manifest_version": 3,
  "name": "CaelestiaSites",
  "version": "1.0",
  "description": "Dynamic webpage theming using Matugen colors",
  "browser_specific_settings": {
    "gecko": {
      "id": "caelestiasites@dim.contact",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "permissions": [
    "nativeMessaging",
    "storage",
    "tabs",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_popup": "popup.html",
    "default_title": "CaelestiaSites"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start"
    }
  ]
}