* Update the contributors list.
* Update the version number.
* Sync zh and zh-hant versions.
* Move epub builder to the utils branch.
* Optimize all figure files using pngquant.
* Update copyright.
* Update Acknowledgements.
* Update buttons in README.
* Review the EN heading format.
* Fix pythontutor headings.
* Fix pythontutor headings.
* bug fixes
* Fix headings in **/summary.md
* Revisit the CN-to-EN translation for Python code using Claude-4.5
* Revisit the CN-to-EN translation for Java code using Claude-4.5
* Revisit the CN-to-EN translation for Cpp code using Claude-4.5.
* Fix the dictionary.
* Fix cpp code translation for the multipart strings.
* Translate Go code to English.
* Update workflows to test EN code.
* Add EN translation for C.
* Add EN translation for CSharp.
* Add EN translation for Swift.
* Trigger the CI check.
* Revert.
* Update en/hash_map.md
* Add the EN version of Dart code.
* Add the EN version of Kotlin code.
* Add missing code files.
* Add the EN version of JavaScript code.
* Add the EN version of TypeScript code.
* Fix the workflows.
* Add the EN version of Ruby code.
* Add the EN version of Rust code.
* Update the CI check for the English version code.
* Update Python CI check.
* Fix cmakelists for en/C code.
* Fix Ruby comments
* Add "reference" for EN version. Bug fixes.
* Unify the figure reference as "the figure below" and "the figure above".
Bug fixes.
* Format the EN markdown files.
* Replace "" with <u></u> for EN version and bug fixes
* Fix biary_tree_dfs.png
* Fix biary_tree_dfs.png
* Fix zh-hant/biary_tree_dfs.png
* Fix heap_sort_step1.png
* Sync zh and zh-hant versions.
* Bug fixes
* Fix EN figures
* Bug fixes
* Fix the figure labels for EN version