Examine source code of Night Mode

{
  "manifest_version": 3,
  "name": "Night Mode",
  "version": "1.0",
  "description": "A Simple, Warm, and Lightweight Night Mode",
  "author": "Kyphion",
  "homepage_url": "https://github.com/Kyphion",
  "incognito": "spanning",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "icons": {
    "16": "Icons/icon16.png",
    "32": "Icons/icon32.png",
    "48": "Icons/icon48.png",
    "96": "Icons/icon96.png",
    "128": "Icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "nightmode@kyphion"
    }
  }
}