Examine source code of Image Link Previewer

{
  "manifest_version": 3,
  "name": "Image Link Previewer",
  "version": "1.0",
  "description": "Hover over a link to preview all images from the destination URL.",
  "permissions": [
    "activeTab",
    "scripting",
    "tabs",
    "storage"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "preview.css"
      ]
    }
  ],
  "action": {
    "default_popup": "popup.html",
    "default_title": "Image Link Previewer"
  },
  "icons": {
    "48": "icons/icon-48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "huynhphuquy712001asus4.4.2@gmail.com"
    }
  }
}