Complete the autogenerated CRD descriptions

[mflendrich]

Problem Statement

CRDs generated by Kubebuilder have description fields for many of the fields.

These are already a significant improvement over the manually written CRDs from KIC 1.x, but the use of descriptions is not consistent yet (there doesn't seem to be a key for presence or lack of presence of a description on specific fields).

Proposed Solution

Add descriptions to all fields of all autogenerated CRDs. Alternatively, choose fields not to add descriptions to, in a consequent manner.

Acceptance Criteria

• User of our autogenerated CRDs has a consistent experience when using kubectl explain with all our CRDs.

[randmonkey]

I checked all our 6 CRDs in this repo:

• kongclusterplugin
• kongconsumer
• kongingress
• kongplugin
• tcpingress
• udpingress
  fields of kongingress does not have descriptions, and other CRDs and their fields have descriptions. So we would update the descriptions of kongingress.