[DOCS] Add helm3 install guide

Document helm 3 deployment as our experimental feature.

Issue-ID: OOM-2562
Change-Id: I188f53d7b90657d710109e6966220e0cfb9db8be
Signed-off-by: Jakub Latusek <j.latusek@samsung.com>
[Fix issues reported in review]
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
3 files changed