* translation: Update replace_linear_by_hashing.md
refined some parts of it.
* Update replace_linear_by_hashing.md
* Update replace_linear_by_hashing.md
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Co-authored-by: Yudong Jin <krahets@163.com>
* 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