Move `UStack` to `ustl`

[bleudev]

closes #40

Summary by Sourcery

This pull request renames UStack to Stack throughout the codebase, including updates to the documentation and test cases. Additionally, it simplifies the setup.py script.

• Enhancements:
  • Renamed UStack to Stack across the codebase for consistency and clarity.
• Documentation:
  • Updated documentation to reflect the renaming of UStack to Stack.
• Tests:
  • Modified test cases to use Stack instead of UStack.
• Chores:
  • Simplified the setup.py script by removing the __package function and directly using find_packages().

[sourcery-ai[bot]]

Reviewer's Guide by Sourcery

This pull request renames the UStack class to Stack throughout the codebase, including updates to the documentation and test cases. Additionally, it simplifies the setup.py script by using find_packages().

File-Level Changes

Files	Changes
tests/test_ustack.py ufpy/ustack.py examples/ustack.md	Renamed UStack to Stack across the codebase, including tests and documentation.
setup.py	Simplified the setup.py script by using find_packages() and removing redundant package definitions.

---

Tips

- Trigger a new Sourcery review by commenting `@sourcery-ai review` on the pull request. - Continue your discussion with Sourcery by replying directly to review comments. - You can change your review settings at any time by accessing your [dashboard](https://app.sourcery.ai): - Enable or disable the Sourcery-generated pull request summary or reviewer's guide; - Change the review language; - You can always [contact us](mailto:support@sourcery.ai) if you have any questions or feedback.

[bleudev]

@sourcery-ai review

[bleudev]

@sourcery-ai review