Automatic merge from submit-queue

GroupMetaFactoryArgs documentation

**What this PR does / why we need it**:
Documentation for people writing new API-Groups.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: documentation

**Special notes for your reviewer**:
@deads2k @pmorie my thoughts from writing the service-catalog apiserver.

**Release note**:

```release-note
NONE
```