#36 Update README -- No longer an installation "the Amber way"

Originally at 2015-04-17T06:22:13Z by Hannes Hirzel closed at 2015-04-21T08:54:43Z ``grunt-init-amber`` does not need to be installed directly by the user at all. Update READE.me to reflect this more **clearly**. Simply state ``grunt-init-amber`` is a component which is automatically installed when you install ``amber-cli``. And then refer to the main amber installation [README](https://github.com/amber-smalltalk/amber/blob/master/README.md). @herby : you can assign this to me.