Examine source code of Alt Text Viewer

{
  "manifest_version": 3,
  "name": "__MSG_extensionName__",
  "version": "1.2.0",
  "description": "__MSG_extensionDescription__",
  "default_locale": "en",
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "images/logo16.png",
      "48": "images/logo48.png",
      "128": "images/logo128.png"
    }
  },
  "permissions": [
    "activeTab"
  ],
  "icons": {
    "16": "images/logo16.png",
    "48": "images/logo48.png",
    "128": "images/logo128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "browser-polyfill.js",
        "content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "browser-polyfill.js",
      "background.js"
    ],
    "service_worker": "service-worker.js"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "_locales/*/*.json"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "alt-text-viewer@example.com",
      "strict_min_version": "58.0"
    }
  }
}