ENGDOCS-2143 (#20301)

* ENGDOCS-2143

* Apply suggestions from code review

Co-authored-by: Guillaume Lours <705411+glours@users.noreply.github.com>

---------

Co-authored-by: Guillaume Lours <705411+glours@users.noreply.github.com>

content/compose/startup-order.md

@@ -22,6 +22,38 @@ The solution for detecting the ready state of a service is  to use the `conditio
 - `service_healthy`. This specifies that a dependency is expected to be “healthy”, which is defined with `healthcheck`, before starting a dependent service.
 - `service_completed_successfully`. This specifies that a dependency is expected to run to successful completion before starting a dependent service.
 
+## Example
+
+```yaml
+services:
+  web:
+    build: .
+    depends_on:
+      db:
+        condition: service_healthy
+        restart: true
+      redis:
+        condition: service_started
+  redis:
+    image: redis
+  db:
+    image: postgres
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER} -d ${POSTGRES_DB}'"]
+      interval: 10s
+      retries: 5
+      start_period: 30s
+      timeout: 10s
+```
+
+Compose creates services in dependency order. `db` and `redis` are created before `web`. 
+
+Compose waits for healthchecks to pass on dependencies marked with `service_healthy`. `db` is expected to be "healthy" (as indicated by `healthcheck`) before `web` is created.
+
+The healthcheck for the `db` service uses the `pg_isready -U ${POSTGRES_USER} -d ${POSTGRES_DB}'` command to check if the PostgreSQL database is ready. The service is retried every 10 seconds, up to 5 times.
+
+Compose also removes services in dependency order. `web` is removed before `db` and `redis`.
+
 ## Reference information 
 
 - [`depends_on`](compose-file/05-services.md#depends_on)