Add MIT license and package metadata; tidy README wording

[Code0x58]

Motivation

• Make the project distribution-ready by adding an explicit license and upstream metadata for packaging.
• Improve README copy to emphasize that the library is dependency-free and to polish list formatting for clarity.

Description

• Add a LICENSE file containing the MIT license with copyright attributed to Oliver Bristow (2025).
• Update pyproject.toml to include license = "MIT" and add an appropriate classifiers entry for the MIT license.
• Tweak README.md wording to note the project is dependency-free and reformat several list items for consistency and readability.

Testing

• No automated tests were executed as part of this change.

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Codex Task

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (c9e48d7) to head (27d01f0).
⚠️ Report is 1 commits behind head on master.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff            @@
##            master       #15   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            1         1           
  Lines          195       195           
=========================================
  Hits           195       195           

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