iteration and conditionals - ytt templating

[poblin-orange]

Is your feature request related to a problem? Please describe.

I need to template a list of element

Describe the solution you'd like
a community supported alternative / additional templating solution, like ytt.

• https://developer.ibm.com/blogs/yaml-templating-tool-to-simplify-complex-configuration-management/
• https://content.pivotal.io/blog/introducing-k14s-kubernetes-tools-simple-and-composable-tools-for-application-deployment

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.