Feature suggestion: auto-generate ARM template

I think it would be really helpful if `func init` could optionally create an ARM template, just like it can create a `Dockerfile` with the `--docker` switch.

A good starting point would be to emit an ARM template (similar to [this one](https://github.com/Azure/azure-quickstart-templates/blob/master/101-function-app-create-dynamic/azuredeploy.json
)) that creates the following resources:
- Consumption App Service Plan
- Function App
- correct worker runtime set up (FUNCTIONS_WORKER_RUNTIME)
- Managed Identity enabled
- Storage Account
- App Insights

It should also create:
- A parameters file (supporting overriding the defaults in the ARM template)
- Sample deployment scripts with Azure PowerShell & Azure CLI

Would be a great way to get up and running even faster with a new Function App & the core tools.

Start with the `func init` entry point and its existing `--docker` generation path. Compare the linked Azure quickstart ARM template with the requested Consumption plan, Function App settings, managed identity, storage, and App Insights resources. Done means generating the ARM template, parameters file, and Azure PowerShell and CLI deployment scripts.

Written by the indexing model from the issue text.