* CLICKHOUSE-4063: less manual html @ index.md
* CLICKHOUSE-4063: recommend markdown="1" in README.md
* CLICKHOUSE-4003: manually purge custom.css for now
* CLICKHOUSE-4064: expand <details> before any print (including to pdf)
* CLICKHOUSE-3927: rearrange interfaces/formats.md a bit
* CLICKHOUSE-3306: add few http headers
* Remove copy-paste introduced in #3392
* Hopefully better chinese fonts #3392
* get rid of tabs @ custom.css
* Apply comments and patch from #3384
* Add jdbc.md to ToC and some translation, though it still looks badly incomplete
* minor punctuation
* Add some backlinks to official website from mirrors that just blindly take markdown sources
* Do not make fonts extra light
* find . -name '*.md' -type f | xargs -I{} perl -pi -e 's//g' {}
* find . -name '*.md' -type f | xargs -I{} perl -pi -e 's/ sql/g' {}
* Remove outdated stuff from roadmap.md
* Not so light font on front page too
* Refactor Chinese formats.md to match recent changes in other languages
* Update some links on front page
* Remove some outdated comment
* Add twitter link to front page
* More front page links tuning
* Add Amsterdam meetup link
* Smaller font to avoid second line
* Add Amsterdam link to README.md
* Proper docs nav translation
* Back to 300 font-weight except Chinese
* fix docs build
* Update Amsterdam link
* remove symlinks
* more zh punctuation
* apply lost comment by @zhang2014
* Apply comments by @zhang2014 from #3417
* Remove Beijing link
* rm incorrect symlink
* restore content of docs/zh/operations/table_engines/index.md
* CLICKHOUSE-3751: stem terms while searching docs
