Examine source code of Link Extractor Pro

{
  "manifest_version": 2,
  "name": "Link Extractor",
  "version": "1.0.0",
  "description": "Select an area on a web page with a shortcut key and extract links from it",
  "author": "Your Name",
  "homepage_url": "https://github.com/yourusername/link-extractor",
  "browser_specific_settings": {
    "gecko": {
      "id": "link-extractor@example.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "activeTab",
    "storage",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "commands": {
    "start-selection": {
      "suggested_key": {
        "default": "Alt+Q",
        "mac": "Alt+Q"
      },
      "description": "Start area selection mode"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  }
}