Examine source code of Dark Mode Switcher

{
  "manifest_version": 3,
  "name": "Dark Mode Switcher",
  "version": "1.0.0",
  "description": "Switch between light and dark themes instantly on any website.",
  "author": "Vishwas.R",
  "browser_specific_settings": {
    "gecko": {
      "id": "dark-mode-switcher@vishwas.me"
    }
  },
  "icons": {
    "16": "icons/icon-light-16.png",
    "48": "icons/icon-light-48.png",
    "128": "icons/icon-light-128.png"
  },
  "action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/icon-light-16.png",
      "48": "icons/icon-light-48.png",
      "128": "icons/icon-light-128.png"
    },
    "default_title": "Dark Mode Switcher"
  },
  "permissions": [
    "storage",
    "tabs",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "commands": {
    "toggle-dark-mode": {
      "suggested_key": {
        "default": "Alt+Shift+D"
      },
      "description": "Toggle dark mode on the current tab"
    }
  }
}