Examine source code of Checkbox Controller

{
  "manifest_version": 2,
  "name": "Checkbox Controller",
  "description": "Easily check or uncheck all checkboxes on any website.",
  "version": "1.2",
  "browser_specific_settings": {
    "gecko": {
      "id": "checkbox-controller@applabb.extension",
      "strict_min_version": "79.0"
    },
    "gecko_android": {
      "strict_min_version": "113.0"
    }
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "logo48.png",
      "96": "icon96.png"
    }
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "icons": {
    "48": "logo48.png",
    "96": "icon96.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ]
}