Examine source code of Simple CSS Overwriter

{
  "manifest_version": 3,
  "name": "Simple CSS Overwriter",
  "version": "1.0",
  "permissions": [
    "activeTab",
    "scripting",
    "storage"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icon.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "simple-css-overwriter@piyush",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "48": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ]
}