Added outputs to apigee-x-foundations blueprint (PSC NEGs) (#2705)

Co-authored-by: Ludovico Magnocavallo <ludomagno@google.com>

blueprints/apigee/apigee-x-foundations/README.md

@@ -501,4 +501,5 @@ module "apigee-x-foundations" {
 | [int_lbs](outputs.tf#L71) | Internal LBs. |  |  |
 | [project](outputs.tf#L76) | Project. |  |  |
 | [project_id](outputs.tf#L81) | Project id. |  |  |
+| [psc_negs](outputs.tf#L86) | PSC NEGs. |  |  |
 <!-- END TFDOC -->

blueprints/apigee/apigee-x-foundations/outputs.tf

@@ -82,3 +82,8 @@ output "project_id" {
   description = "Project id."
   value       = module.project.project_id
 }
+
+output "psc_negs" {
+  description = "PSC NEGs."
+  value       = google_compute_region_network_endpoint_group.psc_negs
+}