Examine source code of Simple QR Generator

{
  "manifest_version": 2,
  "name": "Simple QR Generator",
  "version": "1.0",
  "description": "Generates QR code for the current tab URL.",
  "permissions": [
    "tabs"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon16.png",
      "48": "icon48.png",
      "128": "icon128.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5f60d9d7-a1b7-45ff-8a63-6f30be2b45ac}"
    }
  }
}