Examine source code of Look up HTML reference

{
  "manifest_version": 2,
  "name": "Look up HTML reference",
  "description": "Provides a quick and easy way to look up HTML references on WhatWG and MDN reference, then copy the URL as markdown/HTML",
  "version": "2.0.3",
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": "html_ref_icon.png",
    "default_title": "Look up WCAG SCs"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "data-source.js",
        "lookup-functions.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{afccd202-8388-434e-94e0-b2a124af4c03}"
    }
  }
}