Examine source code of GIF Viber

{
  "manifest_version": 2,
  "name": "GIF Viber",
  "description": "Decorate your browser with a GIF",
  "version": "1.1.1",
  "icons": {
    "48": "icon.png",
    "96": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "gif-viber@example.org",
      "strict_min_version": "115.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "browser_action": {
    "default_popup": "hello.html",
    "default_icon": "icon.png"
  },
  "permissions": [
    "activeTab",
    "storage",
    "tabs"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "contentScript.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_security_policy": "default-src 'self'; script-src 'self'; img-src 'self' data: https:; style-src 'self' 'unsafe-inline' https://fonts.googleapis.com https://cdn.jsdelivr.net; font-src 'self' https://fonts.gstatic.com; connect-src 'self';"
}