updates README: in-memory virtual IO example

[jneuendorf-i4h]

Fixes #333

---

Note

I couldn't check the compiled HTML because I got the following error:

python setup.py build_sphinx
python-soundfile/venv/lib/python3.11/site-packages/setuptools/__init__.py:80: _DeprecatedInstaller: setuptools.installer and fetch_build_eggs are deprecated.
!!

        ********************************************************************************
        Requirements should be satisfied by a PEP 517 installer.
        If you are using pip, you can try `pip install --use-pep517`.
        ********************************************************************************

!!
  dist.fetch_build_eggs(dist.setup_requires)
WARNING: The wheel package is not available.
usage: setup.py [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]
   or: setup.py --help [cmd1 cmd2 ...]
   or: setup.py --help-commands
   or: setup.py cmd --help

error: invalid command 'build_sphinx'

If this is not just a problem with my local setup, CONTRIBUTING.rst might need to be adjusted, as well.

[bastibe]

Thank you for alerting me to this issue. At some point, we'll probably need to rewrite the setup.py script to a modern pep517 structure. If you'd like to take a stab at the installation issue, I'd be most grateful for the help, but that has nothing to do with the issue at hand.

As for this pull request, I like your contribution! Thank you very much! The render looks good in Github's renderer, which is good enough. Is this ready to merge on your end?

[jneuendorf-i4h]

Yeah, the documentation is ready to be merged as far as I am concerned. 👍

[bastibe]

Thank you very much!