chore: adds cdn configuration options

Adds CDN configuration options for Azure and GCP Terraform providers.

This enables users to configure CDN settings, including zone names,
domain names, and cache invalidation behavior, to be compatible with
custom domains for website deployments.

Author: davemooreuws

docs/providers/terraform/azure.mdx

@@ -110,6 +110,18 @@ adminemail: [email protected]
 
 # Subscription ID to associate deployed services with
 subscription-id: example-subscription-id
+
+# Add CDN configuration, required for custom domains for website deployments
+# Available since v1.23.0
+cdn:
+  # The name of the Azure DNS Zone to use when configuring the website DNS
+  zone-name: example.com
+  # The resource group name of the DNS Zone you configured in Azure DNS Zones
+  zone-resource-group: yourzone-rg
+  # A valid domain or subdomain for the DNS Zone to use for the deployed websites endpoint
+  domain-name: app.example.com
+  # Skip CDN cache invalidation during deployments (defaults to false)
+  skip-cache-invalidation: true
 ```
 
 <Note>

docs/providers/terraform/gcp.mdx

@@ -87,6 +87,21 @@ gcp-project-id: my-gcp-project-id
 # https://en.wikipedia.org/wiki/List_of_tz_database_time_zones
 schedule-timezone: Australia/Sydney
 
+# Add CDN configuration, required for websites deployments
+# Available since v1.22.0
+cdn:
+  # The name of the Google Cloud DNS Zone to use when configuring the website DNS
+  zone-name: yourzone
+  # A valid subdomain for the DNS Zone to use for the deployed websites endpoint
+  domain-name: app.example.com
+  # The following configuration values are optional
+  # Specify the TTL the CDN sends in the Cache-Control or Expires headers to clients
+  client-ttl: 3600
+  # Specify the TTL for content cached by the CDN when the origin server does not provide any caching directives
+  default-ttl: 604800
+  # Skip CDN cache invalidation during deployments (defaults to false)
+  skip-cache-invalidation: true
+
 # Configure your deployed services
 config:
   # How services without a type will be deployed