Add git setup for `origami new`

[tristanMatthias]

I'm submitting a ...

• bug report
• feature request

For project (Choose one)

• @origami/cli
• @origami/core
• @origami/core-lib
• @origami/core-server
• @origami/origami
• @origami/plugin-core-api
• @origami/tslint-config

What is the current behavior?
Currently no git setup is created for a new Origami project started from CLI

What is the expected behavior?

1. Initialize git
2. Create gitignore file (defaults included)

What is the motivation / use case for changing the behaviour?
Better setup for developers and faster app development