[docs] make visual studio code section more precise
Summary: removed an unnecessary sentence and changed VSCode to Visual Studio Code
Test Plan: docs
Reviewers: geekbrother, atul, ashoat
Reviewed By: atul, ashoat
Subscribers: ashoat, palys-swm, Adrian, karol-bisztyga, benschac, yayabosh
Differential Revision: https://phabricator.ashoat.com/D3603