Examine source code of IPA

{
  "manifest_version": 2,
  "name": "IPA",
  "description": "This Firefox web extension takes full screenshots (i.e. to the bottom of the page) and saves them to PDF files. A dialog window will open to let you set options.",
  "version": "2.1.11",
  "applications": {
    "gecko": {
      "strict_min_version": "57.0"
    }
  },
  "permissions": [
    "<all_urls>",
    "activeTab",
    "downloads",
    "downloads.open"
  ],
  "browser_action": {
    "default_icon": "icon-64.png",
    "default_title": "IPA",
    "browser_style": true
  },
  "sidebar_action": {
    "default_icon": "icon-64.png",
    "default_title": "IPA",
    "default_panel": "dialog/dialog.html"
  },
  "background": {
    "scripts": [
      "background/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_scripts/jspdf.min.js",
        "content_scripts/page2pdf.js",
        "content_scripts/loadingPagePreCapture.js"
      ],
      "all_frames": true
    }
  ],
  "default_locale": "en"
}