Add binary step activation function (#10030)

* Add binary step activation function

* fix: ruff line too long error

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* refactor: add link to directory

* revert: add link to directory

* fix: algorithm bug and docs

* Update neural_network/activation_functions/binary_step.py

* fix: ruff line too long error

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Tianyi Zheng <[email protected]>