fix descriptions in readme.md

[zrq1706]

No description provided.

[Copilot]

Pull Request Overview

This PR bumps the package version to 0.7.4 and updates documentation to reflect the new release, including tweaks to the README and changelog.

• Bump version in __init__.py and pyproject.toml
• Refine README descriptions and formatting
• Add 0.7.4 entry to CHANGELOG.md

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
src/u_stats/init.py	Version updated from 0.7.3 to 0.7.4
pyproject.toml	Version fields updated to 0.7.4
README.md	Simplified bullet text, capitalization fixes, extra blank line added
CHANGELOG.md	New section for 0.7.4 release with fixes listed

Comments suppressed due to low confidence (3)

README.md:11

• [nitpick] The removal of "from exponential to polynomial" omits an explicit performance improvement detail. Consider retaining or rephrasing it to clearly convey the computational complexity reduction.

- Leverages the underlying combinatorial structure of kernel functions to significantly reduce computational complexity in many cases

CHANGELOG.md:1

• [nitpick] The date for the 0.7.4 entry matches the previous version's date, which could be confusing. Please update to the correct release date and ensure chronological order.

## 0.7.4 (2025-07-04)