Examine source code of Copy AllTab URLs

{
  "manifest_version": 2,
  "name": "Copy AllTab URLs",
  "version": "1.0",
  "description": "Copy URLs of all open tabs in the current window",
  "permissions": [
    "tabs",
    "notifications"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_title": "Copy AllTab URLs"
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e7e019d6-f2b9-4ca6-a8fa-74ea516cfbf7}"
    }
  }
}