Module docstring says TagReference but means TagObject

[EliahKagan]

The git.objects.tag module holds the TagObject class that represents tag objects, representing annotated tags, which are git objects, while of course the TagReference class represents lightweight tags, which are git references.

When updating docstrings in 6126997 (#1850), I tried to say this, and even was aware that it was easy to write the wrong identifier while editing multiple docstrings, and I checked for this mistake, yet still it was not enough and I made the docstring say the exact opposite:

GitPython/git/objects/tag.py

Lines 8 to 9 in e880c33

	This defines the :class:`TagReference` class, which represents annotated tags.
	For lightweight tags, see the :mod:`git.refs.tag` module.

A fix for this is included in #1859, at 1cdec7a, and I anticipate that #1859, expanded to properly fix #1858 and integrate changes from other PRs, will be ready for review very soon. Nonetheless I'm opening this issue so that, if it turns out there are delays and a release has to be made, that commit can be cherry-picked or its fix otherwise applied.