Examine source code of Web Extractor

{
  "manifest_version": 2,
  "name": "Web Extractor",
  "version": "1.2",
  "description": "WebExtension to search for links via APIs and find emails and phone numbers on web pages.",
  "permissions": [
    "activeTab",
    "storage",
    "tabs",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "js/libphonenumber-js.min.js",
      "js/background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "img/icon16.png",
      "48": "img/icon48.png",
      "128": "img/icon128.png"
    }
  },
  "icons": {
    "48": "img/icon48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{de985678-9784-48af-ba81-b8fa2ca0a9a8}"
    }
  }
}