Update ns-setup-win.md

[razukc]

refreshenv also worked there.

PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/CONTRIBUTING.md#commit-messages.
• If there is an issue related with this PR, point it out here.

What is the current state of the documentation article?

What is the new state of the documentation article?

Fixes/Implements/Closes #[Issue Number].

[cla-bot]

Thank you for your pull request and welcome to our community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. In order for us to review and merge your code, please sign the CLA at https://www.nativescript.org/cla.
CLA has not been signed by users: @razukc.
After signing the CLA, you can ask me to recheck this PR by posting @cla-bot check as a comment to the PR.

[razukc]

@cla-bot check no, thanks.