Format shared/cli.md
Format shared/cli.md

* fix unecessary newlines and change syntax to shell

* Update languages/exercises/shared/.docs/cli.md

Co-authored-by: Ayato Hayashi <762610554eed3e3a243e18b37f062df1af6aa985@codmon.co.jp>

Co-authored-by: Ayato Hayashi <762610554eed3e3a243e18b37f062df1af6aa985@codmon.co.jp>

exercism/xecmascript,exercism/xecmascript