Examine source code of Tab Manager Shortcut

{
  "manifest_version": 3,
  "name": "Tab Manager Shortcut",
  "version": "1.0",
  "description": "Manage tabs with keyboard shortcuts: close, open, or switch tabs.",
  "permissions": [
    "tabs",
    "commands"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "commands": {
    "close-tab": {
      "suggested_key": {
        "default": "Ctrl+Shift+W"
      },
      "description": "Close the current tab"
    },
    "new-tab": {
      "suggested_key": {
        "default": "Ctrl+Shift+N"
      },
      "description": "Open a new tab"
    },
    "switch-tab-left": {
      "suggested_key": {
        "default": "Ctrl+Shift+Left"
      },
      "description": "Switch to the tab on the left"
    },
    "switch-tab-right": {
      "suggested_key": {
        "default": "Ctrl+Shift+Right"
      },
      "description": "Switch to the tab on the right"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "tab-manager-shortcut@myextension.com"
    }
  }
}