Examine source code of Square Corners Everywhere

{
  "manifest_version": 3,
  "name": "Square Corners Everywhere",
  "version": "1.2.5",
  "description": "Removes rounded corners from websites.",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "action": {
    "default_title": "Square Corners Everywhere",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png"
    },
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "css": [
        "square-corners.css"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start",
      "all_frames": true
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "square-corners-everywhere@local",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {}
  }
}