Add `description` and `hidden` field to profiles

[JamesHutchisonCarta]

Currently, we construct a devspace yaml file by having the default dev profile simply define an empty structure, and then all other profiles patch it. Some profiles are building block profiles, others are "public" profiles. This request is for two features:

• Add an optional hidden field to profiles. This would make it so that they do not show up under devspace list profiles. Currently, we use a leading underscore in the profile name to separate "public" from "private" profiles. Alternatively, do not list profiles with a leading underscore in the name. "hidden" profiles would still be usable as parent profiles, even across projects.
• Add an optional description field to profiles. This could show up when you list profiles so that people have a better understanding on how to use the profile and what it is doing.

[FabianKramm]

@JamesHutchisonCarta thanks for creating this issue! That makes a lot of sense, I agree that we should add this.