Create a new chart for the IngressOperator

[alexellis]

Expected Behaviour

It should be easy to customise the IngressOperator and to install it more than once into varying namespaces.

Current Behaviour

It can be installed once with some defaults and a couple of variables.

Possible Solution

1. Split the chart out into its own folder within the faas-netes repo.
2. Remove the option from the faas-netes chart, and update docs so that users install the new chart.
3. add an arkade app for ingress-operator

Configuration options:

• ingress_namespace
• installation namespace

Context

Customisation request here in #661 doesn't really make sense, since you will often need both, not either or namespaces to be configured.