Examine source code of Shelf Web Clipper

{
  "name": "Shelf Collaborative Web Clipper",
  "version": "1.19.0",
  "manifest_version": 2,
  "description": "This collaborative bookmarking tool is the best way to capture and share web content within your team or across your organization.",
  "icons": {
    "16": "images/icon-16.png",
    "128": "images/icon-128.png"
  },
  "short_name": "ShelfClipper",
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "permissions": [
    "tabs",
    "http://*/*",
    "https://*/*",
    "notifications",
    "storage",
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "css": [
        "lib/jcrop/jquery.Jcrop-theme.css"
      ],
      "js": [
        "node_modules/jquery/dist/jquery.min.js",
        "lib/jcrop/jquery.Jcrop.min.js",
        "scripts/contentscript.js"
      ],
      "run_at": "document_end",
      "all_frames": false
    }
  ],
  "browser_action": {
    "default_icon": {
      "19": "images/icon-19.png",
      "38": "images/icon-38.png"
    }
  },
  "web_accessible_resources": [
    "images/icon-48.png",
    "/images/Shelf.io_512x512_with_text.svg",
    "/images/card-background-video.png",
    "iframe.html",
    "folder-picker-frame.html",
    "rich-text-editor.html",
    "cropper.html",
    "image-picker.html",
    "video-picker.html",
    "fail.html",
    "success.html",
    "Settings.json"
  ],
  "homepage_url": "https://shelf.io/",
  "applications": {
    "gecko": {
      "id": "production@gemshelf.com",
      "strict_min_version": "55.0"
    }
  }
}