feat: implement manacher's algorithm and test script, update readme file

[codomposer]

Add Manacher's Algorithm for Longest Palindromic Substring

Summary

This PR implements Manacher's Algorithm, a linear-time O(n) algorithm for finding the longest palindromic substring in a string. This is a significant improvement over the naive O(n²) approach.

What's Added

• Algorithm Implementation (Algorithms/Strings/ManachersAlgorithm.cs):

  • FindLongestPalindrome() - Returns the longest palindromic substring
  • FindLongestPalindromeWithDetails() - Returns palindrome with position details
  • IsPalindrome() - Checks if entire string is a palindrome
  • Comprehensive inline documentation explaining the algorithm's logic

• Comprehensive Test Suite (Algorithms.Tests/Strings/ManachersAlgorithmTests.cs):

  • 28 test cases covering:
    • Odd and even-length palindromes
    • Edge cases (empty, single character, no palindromes)
    • Special characters and numeric strings
    • Performance validation with long strings

• Documentation:

  • Updated README.md with link to the new algorithm
  • Detailed docstrings explaining key concepts and complexity
  • Step-by-step algorithm breakdown with examples

Algorithm Details

• Time Complexity: O(n) - Each character examined at most twice
• Space Complexity: O(n) - For transformed string and radius array
• Reference: "A New Linear-Time On-Line Algorithm for Finding the Smallest Initial Palindrome of a String" by Glenn Manacher (1975), Journal of the ACM

Testing

All tests pass successfully:

• ✅ 28 new Manacher's Algorithm tests
• ✅ 12,252 total repository tests passing
• ✅ 0 warnings, 0 errors
• ✅ StyleCop compliance maintained

Checklist

• I have performed a self-review of my code
• My code follows the style guidelines of this project
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Comments in areas I changed are up to date
• I have added comments to hard-to-understand areas of my code
• I have made corresponding changes to the README.md

Fixes

Closes #465
Closes #549

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.85%. Comparing base (3e4cdb2) to head (d92d7a7).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #554      +/-   ##
==========================================
+ Coverage   96.81%   96.85%   +0.03%     
==========================================
  Files         286      287       +1     
  Lines       11753    11861     +108     
  Branches     1687     1706      +19     
==========================================
+ Hits        11379    11488     +109     
  Misses        237      237              
+ Partials      137      136       -1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[codomposer]

@siriak Could you please take a look this PR?

[siriak]

Looks good, thanks!