* 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* Remove outdated stuff from roadmap.md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
* Some improvements for introduction/performance.md
* Minor improvements for example_datasets
* Add website/package-lock.json to .gitignore
* YT paragraph was badly outdated and there is no real reason to write a new one
* Use weird introduction article as a starting point for F.A.Q.
* Some refactoring of first half of ya_metrika_task.md
* minor
* Weird docs footer bugfix
* Forgotten redirect
* h/v scrollbars same size in docs
* CLICKHOUSE-3831: introduce security changelog
* A bit more narrow tables on docs front page
* fix flag in ru docs
* Save some space in top level of docs ToC
* Capitalize most words in titles of docs/en/
* more docs scrollbar fixes
* fix incorrect merge
* fix link
* fix switching languages in single page docs mode
* Update mkdocs & mkdocs-material + unminify javascript
* cherrypick 17e18d1ecc