Review quick start based on operator based deployment

[maleck13]

What

Once the operator work lands, we should review how our quick start works and see can we improve it for users to be able to quickly try and demo the gateway

[david-martin]

The operator is being made available in 0.5.1
Changes to the helm quickstart and deploy_openshift scripts landed to ensure they work with the latest operator changes (#658)

This issue is worth keeping for the 0.6 timeframe to assess the existing installation material in our docs as a whole, and if the quickstart as it currently stands is the best experience (as it is helm based).