refactor: change folder structure for examples

examples/postgres/base.compose.yml

@@ -0,0 +1,15 @@
+services:
+  postgres:
+    image: git.fastwaydata.com/esauflores/db-postgres:base
+    restart: unless-stopped
+    environment:
+      POSTGRES_USER: ${POSTGRES_USER:-postgres}
+      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-postgres}
+      POSTGRES_DB: ${POSTGRES_DB:-postgres}
+    ports:
+      - "${POSTGRES_PORT:-5432}:5432"
+    volumes:
+      - postgres-data:/var/lib/postgresql
+
+volumes:
+  postgres-data: