Update docker-compose.yml for user and pass of postgreSQL

Author: toru-kurahashi2

.devcontainer/docker-compose.yml

@@ -25,8 +25,8 @@ services:
       - postgres-data:/var/lib/postgresql/data
     environment:
       POSTGRES_PASSWORD: postgres
-      POSTGRES_USER: postgres
-      POSTGRES_DB: postgres
+      POSTGRES_USER: root
+      POSTGRES_DB: todo_app
 
     # Add "forwardPorts": ["5432"] to **devcontainer.json** to forward PostgreSQL locally.
     # (Adding the "ports" property to this file will not forward from a Codespace.)