This reverts commit cdb2c8a7.

This reverts commit 0704da57, reversing
changes made to 4534d449.

* Updating of english translation.

* Some bugs are fixed.

* 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* YT paragraph was badly outdated and there is no real reason to write a new one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 https://github.com/olivernn/lunr.js/commit/17e18d1ecc8a0b44e08cd088c979acd2598d80da

* Additional .gitignore entries

* Merge a bunch of small articles about system tables into single one

* Merge a bunch of small articles about formats into single one

* Adapt table with formats to English docs too

* Add SPb meetup link to main page

* Move Utilities out of top level of docs (the location is probably not yet final) + translate couple articles

* Merge MacOS.md into build_osx.md

* Move Data types higher in ToC

* Publish changelog on website alongside documentation

* Few fixes for en/table_engines/file.md

* Use smaller header sizes in changelogs

* Group up table engines inside ToC

* Move table engines out of top level too

* Specificy in ToC that query language is SQL based. Thats a bit excessive, but catches eye.

* Move stuff that is part of query language into respective folder

* Move table functions lower in ToC

* Lost redirects.txt update

* Do not rely on comments in yaml + fix few ru titles

* Extract major parts of queries.md into separate articles

* queries.md has been supposed to be removed

* Fix weird translation

* Fix a bunch of links

* There is only table of contents left

* "Query language" is actually part of SQL abbreviation

* Change filename in README.md too

* fix mistype