Add doc on using the Azure CDK

[davidfowl]

We have a document on how to use the low-level bicep resource https://learn.microsoft.com/en-us/dotnet/aspire/deployment/azure/custom-bicep-templates. We should expand it to include the basics of the azure provisioning APIs.

NOTE: These APIs are still in preview.

cc @tg-msft @JoshLove-msft

[IEvangelist]

Can we wait until these APIs are non-preview? Less churn.

[davidfowl]

@tg-msft Do we have any basic docs being worked on for the azure.provisioning libs?

[IEvangelist]

@tg-msft Do we have any basic docs being worked on for the azure.provisioning libs?

We do not...

[tg-msft]

We'll be adding basic docs and samples in our repo in the next week that'll get mirrored to our ref docs.