Plate logo in docs/source/_static

Very optional (and slightly tangential to the PR focus): consider using the directory under `docs/source/_static` for storing the logo images (matching the `dataflow` markdown image below) and related reference within the root readme to match. Sphinx recognizes the `_static` dir as a common media location when rendering the docs. This would help keep the documentation images in the same spot.

Note: if you opt for this, it might be that the `docs/source/_static/logo/README.md` file within the logo dir needs to be added to the conf.py `excludes_patterns` list so it isn't referenced through Myst builds.

_Originally posted by @d33bs in https://github.com/cytomining/CytoTable/pull/73#discussion_r1251268444_