User can follow instructions on how to use template-infra with either of the template applications

# Context
Now that we split up the infra and application templates, we need to help the user of the platform understand how to use the two pieces together. We'll probably need to provide some instructions (and perhaps some tools if applicable) for the user to be able to use the template-infra with either of the template applications (template-application-nextjs or template-application-flask).