Improve Windows editor documentation with specific examples for popular editors

Summary: See D2955, D2956, D2957.

Test Plan: Read documentation. Ran all these commands from Git Bash and cmd.exe and used the specified editors to edit blocks of text.

Reviewers: btrahan, jungejason

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T1309

Differential Revision: https://secure.phabricator.com/D2958