Examine source code of Media Magnifier

{
  "manifest_version": 2,
  "name": "Media Magnifier",
  "version": "1.0.1",
  "description": "Smooth scroll-to-zoom (to any level) and drag-to-pan for images, GIFs, and videos opened directly in a tab.",
  "browser_specific_settings": {
    "gecko": {
      "id": "media-magnifier@therin.irwin",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "48": "icon.svg",
    "96": "icon.svg"
  },
  "permissions": [
    "menus",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*",
        "file:///*"
      ],
      "js": [
        "magnifier.js"
      ],
      "css": [
        "magnifier.css"
      ],
      "run_at": "document_end",
      "all_frames": true,
      "match_about_blank": true
    }
  ]
}