[docs:spelling,grammar] README-Unicode.md: Fix spelling and grammar

[bernhardkaindl]

Pull Request Overview (GitHub Copilot PR review)

This PR fixes spelling and grammar issues in the README-Unicode.md file to improve documentation clarity and readability.

• Corrects article usage from "an UTF-8" to "a UTF-8"
• Fixes spelling errors, including "sitation" to "This happens", "especailly" to "especially", "my" to "may", "themself" to "themselves", and "form" to "from"
• Improves sentence structure for better readability

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@          Coverage Diff           @@
##           master    #180   +/-   ##
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  Coverage    83.3%   83.3%           
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  Files          23      23           
  Lines        3347    3347           
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  Hits         2790    2790           
  Misses        557     557           

[Copilot]

Pull Request Overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

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