add launch.json for VSCode

[pcostantini]

launch.json for VSCode that enables F5 experience.

[azurecla]

Hi @pcostantini, I'm your friendly neighborhood Azure Pull Request Bot (You can call me AZPRBOT). Thanks for your contribution!

In order for us to evaluate and accept your PR, we ask that you sign a contribution license agreement. It's all electronic and will take just minutes. I promise there's no faxing. https://cla.azure.com.

TTYL, AZPRBOT;