keyvault-acmebot with vnet integration

[sagar-221B]

Is your feature request related to a problem? Please describe.
In the current deployment of keyvault-acmebot my function app and KeyVault are both public i.e. no Vnet integration.

Describe the solution you'd like
I want a deployment option where if I provide the Vnet and subnet details my Function App and Key Vault should be vnet integrated and not accessible publicly.

Describe alternatives you've considered
Manually making them priavte on the portal but it breaks the whole setup.

[JohnLBevan]

If you make use of the flex consumption plan you can do this: #624