Examine source code of URL Collector

{
  "manifest_version": 2,
  "name": "URL Collector",
  "version": "2.1",
  "description": "Collect URLs and endpoints from a webpage.",
  "icons": {
    "50": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{598061dc-e503-4c81-9640-133c2d6a80de}"
    }
  }
}