Update variable and output descriptions for all modules

[hknutsen]

Now that the modules have been published to the public Terraform Registry, we should ensure that variable and output descriptions are clear, concise and consistent. See variables and outputs best practices for reference.

We could force this as a patch release (how-to force release).

• chore: update variable and output descriptions terraform-azurerm-key-vault#88
• app-insights (looks good to me)
• chore: update variable and output descriptions terraform-azurerm-web-app#179
• chore: update variable and output descriptions terraform-azurerm-sql#139
• fix: validate variable values terraform-azurerm-app-config#27
• refactor: update variable and output descriptions and validations terraform-azurerm-storage#218
• public-ip (looks good to me)
• docs: update variable description terraform-azurerm-nat#18
• chore: update variable descriptions terraform-azurerm-log-analytics#49
• chore: update variable descriptions and add features list terraform-azurerm-acr#75
• chore: update variable descriptions and add features list terraform-azurerm-automation#53
• network (looks good to me)
• docs: update variable descriptions and add features list terraform-azurerm-grafana#37
• event-grid
• synapse
• chore: update variable and output descriptions terraform-azurerm-service-bus#60
• postgres
• chore: update variable and output descriptions terraform-azurerm-function-app#72
• chore: update variable descriptions and add features list terraform-azurerm-databricks#40
• docs: update variable descriptions terraform-azurerm-vm#50
• chore: update variable descriptions and add features list terraform-azurerm-app-service#18
• chore: update variable descriptions and add features list terraform-azurerm-app-config#33
• identity
• container-app
• azuread/app

[hknutsen]

Putting on hold until anyone picks this up and actively works on it again.