Document --connected_blocks for KaFFPa and KaFFPaE in README

Add connected blocks to the use case table, add example run, and
clarify the feature applies to both KaFFPa and KaFFPaE.

Add Python 3.14 wheel builds

KaHIP v3.23

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Update README for KaHIP v3.21

Updated version number from v3.20 to v3.21 and added usage instructions for pip installation.

Merge pull request #165 from alexandersvozil/python-pypi-package

Python pypi package

Merge pull request #156 from qbisi/master

CMakeLists.txt: support installing python module

Update README.md

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Update README.md