examples/jamstack: implemented database integration with RDS

Signed-off-by: Sam Alba <sam.alba@gmail.com>

examples/jamstack/backend.cue

@@ -2,30 +2,9 @@ package main
 
 import (
 	"dagger.io/dagger"
-	"dagger.io/aws"
 	"dagger.io/aws/ecs"
 )
 
-infra: {
-	// AWS auth & default region
-	awsConfig: aws.#Config
-
-	// VPC Id
-	vpcId: string
-
-	// ECR Image repository
-	ecrRepository: string
-
-	// ECS cluster name
-	ecsClusterName: string
-
-	// Execution Role ARN used for all tasks running on the cluster
-	ecsTaskRoleArn?: string
-
-	// ELB listener ARN
-	elbListenerArn: string
-}
-
 // Backend configuration
 backend: {
 	// Source code to build this container