Examine source code of Quick Tab Switcher

{
  "manifest_version": 2,
  "name": "Quick Tab Switcher",
  "version": "1.4.0",
  "description": "A quick tab switcher for Firefox",
  "browser_specific_settings": {
    "gecko": {
      "id": "quick-tab-switcher@r01"
    }
  },
  "icons": {
    "96": "icons/icon-96.png"
  },
  "background": {
    "scripts": [
      "background.bundle.js"
    ]
  },
  "permissions": [
    "storage",
    "tabs",
    "sessions"
  ],
  "browser_action": {
    "browser_style": true,
    "default_popup": "popup.html",
    "default_icon": {
      "96": "icons/icon.png"
    },
    "theme_icons": [
      {
        "light": "icons/icon-light.png",
        "dark": "icons/icon.png",
        "size": 96
      }
    ]
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+B"
      }
    }
  }
}