* Capitalize all the headers, list headers and figure captions
* Fix the term "LRU"
* Fix the names of source code link in avl_tree.md
* Capitalize only first letter for nav trees in mkdocs.yml
* Update code comments
* Update linked_list.md
* Update linked_list.md
* 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
* Update pythontutor block with the latest code
* Move docs-en to en/docs
* Move mkdocs.yml and README to en folder
* Fix en/mkdocs.yml
* Update the landing page
* Fix the glossary
* Reduce the font size of the code block tabs
* Add Kotlin blocks to en/docs
* Fix the code link in en/.../deque.md
* Fix the EN README link