Fix plurality in command docs

refs #89686

Fixes #28624

Manually fixed in docs at https://github.com/microsoft/vscode-docs/pull/3379.

Fixes #89541.

Fixes https://github.com/microsoft/vscode/issues/89424

@sandy081 and @joaomoreno

Lint rules that enforce our api-guidelines

Fixes cannot undo in SCM input box

* Run web against actual server

Part of #80308

* Fix strict null check errors

* Fix folder arg

* Disable unit tests and integration tests temporarily

* Allow running on node 12

* Fix smoke test condition

* Disable continue on error

* Add web to server dir

* fix smoke test to use build for web

* enable in product build
Co-authored-by: NBenjamin Pasero <benjamin.pasero@gmail.com>

* smoke test - carefuly select untitled content based on file name to find it properly

* Fileservice: mkdirp() logic is prone to errors from race conditions (fixes #89834)