Implement custom project support in Kitura CLI

### Context & Description

Currently, `kitura init` runs the generator using `npx`. It would be nice to also allow users to scaffold a project from an arbitrary git repository.

This would look like:

`kitura init --clone https://www.github.com/username/project`

Under the covers this would do `git clone https://www.github.com/username/project`.

## Clear & Actionable Tasks
- [ ] Enhance `kitura init` to allow scaffolding from arbitrary projects
- [ ] Tag new version and publish to NPM