[Nagini-dotcom]

Summary

• Add a new hashing utility in fixit/hashing.py.
• Support MD5, SHA1, and SHA256 algorithms.
• Add a hash CLI subcommand with SHA256 as the default.
• Add tests for supported algorithms, empty input, and invalid algorithms.

Tests

• python -m pytest tests/test_hashing.py — 5 passed.
• The full test suite currently encounters an unrelated missing fixit.roman module.

Closes #94

[Nagini-dotcom]

Hi! I wanted to confirm something regarding my PR #94. I merged it, but later my friends mentioned that contributors should wait for the maintainer to merge PRs and that we should wait until all contributions are reviewed.

I'm sorry if I misunderstood the contribution process. Please let me know if any action is needed from my side. Thank you!