Docs feedback: Add helm3/k8s 1.16+ restrictions
### Problem to solve
Please add to https://docs.gitlab.com/charts/ that the chart currently does not support 1.16+ kubernetes, or Helm3. I just wasted 3 hours trying to figure out what I was missing.
### Proposal
Please add to https://docs.gitlab.com/charts/ that the chart currently does not support 1.16+ kubernetes, or Helm3. I just wasted 3 hours trying to figure out what I was missing.
### Who can address the issue
### Other links/references
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issue