Examine source code of Image alt text badge

{
  "manifest_version": 3,
  "name": "Image alt text badge",
  "short_name": "Img alt text",
  "version": "1.0.1",
  "description": "Overlay alt text badges on every image — follows carousels, modals & SPA navigation. Great for a11y audits.",
  "homepage_url": "https://github.com/lucerowb/image-alt-text-badge",
  "permissions": [
    "activeTab",
    "storage",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "image-alt-text-badge.srijan97@gmail.com",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  },
  "action": {
    "default_popup": "popup.html",
    "default_title": "Image alt text badge",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  }
}