Notify significant projects that still refer to python-igraph instead of igraph

[szhorvat]

On PyPI, python-igraph was renamed to igraph in October 2021. The standard way to install igraph is now:

pip install igraph

The python-igraph name was kept functional, with the intention to terminate support in September 2022. However, as of today (July 2023), over a third of downloads are still through python-igraph:

• https://pypistats.org/packages/igraph
• https://pypistats.org/packages/python-igraph

Here's the the fraction of python-igraph downloads based on a 2-week moving average:

This issue is to notify downstream igraph users (packages, educational resources, etc.) to start using the new name.

[szhorvat]

• py4cytoscape, see https://github.com/search?q=repo%3Acytoscape%2Fpy4cytoscape+python-igraph&type=code
• scanpy
• pygraphistry, fix: change python-igraph package name to igraph in setup.py graphistry/pygraphistry#494
• scvelo, python-igraph is renamed to igraph theislab/scvelo#1099
• plotly, python-igraph was renamed to igraph plotly/plotly.py#4285
• https://github.com/cctbx/cctbx_project/, see https://github.com/cctbx/cctbx_project/blob/master/mmtbx/domains_from_pae.py#L199
• starcal, change python-igraph to igraph ilius/starcal#72
• scikit-multilearn, refer to igraph instead of python-igraph in docs scikit-multilearn/scikit-multilearn#299