Examine source code of HoverPeek

{
  "description": "Shows a preview of a link in iframe",
  "manifest_version": 2,
  "name": "HoverPeek",
  "version": "1.3",
  "homepage_url": "https://github.com/jarusll/hoverpeek.git",
  "icons": {
    "32": "icons/hoverpeek.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "peek.js"
      ]
    }
  ],
  "permissions": [
    "storage",
    "activeTab",
    "http://*/*",
    "https://*/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "type": "module"
  },
  "browser_action": {
    "default_icon": {
      "32": "icons/hoverpeek.png"
    },
    "default_title": "HoverPeek",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{bd9e723c-3b9f-4199-9cd1-a8a89203aba7}"
    }
  }
}