Examine source code of Web Browsing Toolbox

{
  "browser_specific_settings": {
    "gecko": {
      "id": "toolbox@hikohata",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "manifest_version": 3,
  "name": "__MSG_extensionName__",
  "author": "Hiroyuki Kohata",
  "version": "1.6.0",
  "description": "__MSG_extensionDescription__",
  "permissions": [
    "activeTab",
    "scripting",
    "declarativeNetRequest",
    "clipboardWrite",
    "storage",
    "browsingData",
    "webNavigation",
    "tabs",
    "alarms"
  ],
  "background": {
    "scripts": [
      "js/polyfill.js",
      "js/background.js"
    ]
  },
  "action": {
    "default_popup": "html/popup.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/polyfill.js",
        "js/sticky_notes.js",
        "js/notifications.js"
      ],
      "css": [
        "css/notifications.css"
      ],
      "run_at": "document_end"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "js/notifications.js",
        "css/notifications.css"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "icons": {
    "16": "icons/icon-16.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "default_locale": "en"
}