Examine source code of Image Alt QuickView

{
  "manifest_version": 2,
  "name": "Image Alt QuickView",
  "short_name": "Alt QuickView",
  "description": "Quickly view the alternative text of any image in the context menu. Simply right-click on an image.",
  "version": "1.0.2resigned1",
  "permissions": [
    "contextMenus",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "browser-polyfill.js",
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "all_frames": true,
      "js": [
        "browser-polyfill.js",
        "content.js"
      ]
    }
  ],
  "icons": {
    "16": "icon-16.png",
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{486dfbad-64bd-4828-92f1-9d9ca713d713}"
    }
  }
}