Examine source code of Website Scroll Screenshot

{
  "manifest_version": 2,
  "name": "Full Page Screenshot / Website Screenshot",
  "version": "1.0",
  "description": "Take a full or partial screenshot of any webpage & save as png or pdf",
  "permissions": [
    "activeTab",
    "tabs",
    "<all_urls>"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icons/icon-48.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "browser_specific_settings": {
    "gecko": {
      "id": "full-page-website-screenshot@addon.com"
    }
  }
}