Explain why resource code generation is separate 🥚
Explain why resource code generation is separate 🥚

The `resource` package exists to not have dependency cycle between the
different version of the `pipeline` api package. This follows up the
previous change with some comments on why we need to have additional
generation commands.

Signed-off-by: Vincent Demeester <b98c0fd48a8945096c766de790fe70420dd2f223@redhat.com>

tektoncd/pipeline,tektoncd/pipeline