gh-123834: Add `symtable` to the list of modules with a CLI (#123835)

Doc/library/cmdline.rst

diff --git a/Doc/library/cmdline.rst b/Doc/library/cmdline.rst
index dd538cd..78fe95a 100644
--- a/Doc/library/cmdline.rst
+++ b/Doc/library/cmdline.rst
@@ -40,6 +40,7 @@
 * :mod:`runpy`
 * :ref:`site <site-commandline>`
 * :ref:`sqlite3 <sqlite3-cli>`
+* :ref:`symtable <symtable-cli>`
 * :ref:`sysconfig <sysconfig-cli>`
 * :mod:`tabnanny`
 * :ref:`tarfile <tarfile-commandline>`