/**
 * The detected shell type of the {@link Terminal}. This will be `undefined` when there is
 * not a clear signal as to what the shell is, or the shell is not supported yet. This
 * value should change to the shell type of a sub-shell when launched (for example, running
 * `bash` inside `zsh`).
 *
 * Note that the possible values are currently defined as any of the following:
 * 'bash', 'cmd', 'csh', 'fish', 'gitbash', 'julia', 'ksh', 'node', 'nu', 'pwsh', 'python',
 * 'sh', 'wsl', 'zsh'.
 */
readonly shell: string | undefined;