Examine source code of URL Display Extension

{
  "manifest_version": 3,
  "name": "URL Display Extension",
  "version": "1",
  "description": "Shows a button with the URL when entering a new page.",
  "permissions": [
    "tabs",
    "activeTab",
    "scripting"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "icons": {
    "48": "icon.png"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "icon.png",
        "icon1.png",
        "icon2.png"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{daf44bf7-a45e-4450-afc0-25d9ba3b42a2}"
    }
  }
}