Examine source code of Email Extractor

{
  "manifest_version": 2,
  "name": "Email Extractor",
  "short_name": "Email Extractor",
  "description": "Automated Email Extraction Tool which extracts email addresses from web pages and AutoSaves them to use anytime.",
  "version": "2.1",
  "background": {
    "scripts": [
      "jquery-3.4.1.min.js",
      "background.js"
    ]
  },
  "permissions": [
    "storage",
    "tabs",
    "unlimitedStorage",
    "activeTab",
    "http://*/",
    "http://*/*",
    "https://*/*",
    "notifications",
    "<all_urls>",
    "downloads",
    "downloads.open"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "jquery-3.4.1.min.js",
        "content.js"
      ]
    }
  ],
  "icons": {
    "16": "images/icon16.png",
    "32": "images/icon32.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "images/icon16.png",
      "32": "images/icon32.png",
      "48": "images/icon48.png",
      "128": "images/icon128.png"
    },
    "default_title": "Email Extractor",
    "default_popup": "popup.html"
  }
}