[hlx init] should create minimal example

[tripodsan]

hlx init should only create minimal example or even be removed completely.
More sophisticated examples can always be cloned from git.

eg:

$ hlx init my-test

+ creating my-test                 [ok]
+ creating my-test/index.md        [ok]
+ creating my-test/src/html.htl    [ok]
+ creating my-test/src/html.pre.js [ok]

Helix project 'my-test' initialized successfully with a simple example.
For more examples, clone or fork one from https://github.com/adobe/project-helix/.

Next Step: start the development server and test the generated site with:
$ cd my-test
$ hlx up

/cc @davidnuescheler