docs(examples): rename and update documentation

[lumirlumir]

This pull request includes renaming and updating documentation for the solutions-readline examples to reflect changes in module support and directory structure. The most important changes include renaming directories and files, updating documentation references, and adding new README files for ESM module examples.

Renaming and updating documentation:

• Renamed examples/solutions-readline to examples/solutions-readline-cjs and updated all references in README.en.md and README.md to reflect the new directory name. [1] [2] [3] [4]
• Updated package.json to reflect the new name examples-solutions-readline-cjs.

Adding new README files:

• Added README.en.md and README.md for examples/solutions-readline-esm to provide documentation for ESM module examples, including instructions on running the examples and clarifying the lack of ESM support in the Baekjoon Node.js environment. [1] [2]

[github-actions]

Labels have been automatically applied based on the conventional commit types.🏷️

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.92%. Comparing base (4337944) to head (779ec56).
Report is 1 commits behind head on main.

@@           Coverage Diff           @@
##             main      #46   +/-   ##
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  Coverage   90.92%   90.92%           
=======================================
  Files           5        5           
  Lines         617      617           
=======================================
  Hits          561      561           
  Misses         56       56           

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