Bring back CRD descriptions

[james-callahan]

As mentioned at #10116 (comment)

Bring back CRD description fields. They are used by e.g. kubectl explain which is quite useful.

Instead perhaps strip the large fields out as part of the helm chart, rather than removing them for all users just to work around a helm design shortcoming.

[caseydavenport]

Agree these should come back. I'd like to see about ways to do this that will also work with our helm users, if possible. Need to do some brainstorming here.