* Add Ruby code blocks to documents
* Remove Ruby code from en/docs
* Remove "center-table" class in index.md
* Add "data-toc-label" to handle the latex heading during the build process
* Use normal JD link instead.
* Bug fixes
* Sync recent changes to the revised Word.
* Revised the preface chapter
* Revised the introduction chapter
* Revised the computation complexity chapter
* Revised the chapter data structure
* Revised the chapter array and linked list
* Revised the chapter stack and queue
* Revised the chapter hashing
* Revised the chapter tree
* Revised the chapter heap
* Revised the chapter graph
* Revised the chapter searching
* Reivised the sorting chapter
* Revised the divide and conquer chapter
* Revised the chapter backtacking
* Revised the DP chapter
* Revised the greedy chapter
* Revised the appendix chapter
* Revised the preface chapter doubly
* Revised the figures
* Update Dockerfile for code debugging.
* Format Python code using Black.
* Improve dark theme by defining html classes for the figures, animations and cover images.
* Fix several glossary translation.
* Update a code comment.
* Fix climbing_stairs_backtrack: the pruning should not require the sorted choices list.
* Update the code of array and list traversal.
* Fix a rendering issue of README.md
* Update code of list traversal.
* Fix array_definition.png
* Update README.md
* Fix max_capacity_moving_short_board.png
* Fix array.dart
* Fix array.dart
* Fix array.dart
* Fix array.dart
