[issue41224] Document is_annotate() in symtable and update doc strings

[Andrés Delfino]

Change by Andrés Delfino <adelfino at gmail.com>:


----------
pull_requests: +22857
pull_request: https://github.com/python/cpython/pull/24017

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue41224>
_______________________________________