We hypothesize that many first-time users creating a new project will look at the README.md as a starting point for "what next". As we've updated our documentation particularly for new users, having better links to our codelabs and cookbooks will help them be productive.
Allows the user to specify the kind of project to create. The default is 'app'. Other choices are 'plugin' (the old '--plugin' behavior), and 'package'.
A Flutter 'package' is a Dart package that depends on Flutter, but does not contain native code.
Fixes#10377.
