Examine source code of Moodle Dark Mode

{
  "manifest_version": 2,
  "name": "Moodle Dark Mode",
  "version": "3.2",
  "icons": {
    "128": "icon.png"
  },
  "description": "Dark Mode for Moodle. This works on any Moodle page.",
  "content_scripts": [
    {
      "css": [],
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "./content_script.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{358c3cb4-58f9-4335-a92d-acf22902aa05}"
    }
  }
}