Examine source code of Spacebar Drag

{
  "manifest_version": 3,
  "browser_specific_settings": {
    "gecko": {
      "id": "@spacebar-drag",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "name": "Spacebar Drag",
  "version": "1.1",
  "description": "Use spacebar to scroll the window around with precision.",
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": "images/icon_512.png"
  },
  "icons": {
    "16": "images/icon_16.png",
    "48": "images/icon_48.png",
    "128": "images/icon_128.png"
  }
}