add database schema and update docker-compose for initialization

docker-compose.yml

@@ -1,7 +1,7 @@
 services:
   postgres:
     image: postgres:16
-    container_name: ethnograph-postgres
+    container_name: ethnograph-db
     restart: unless-stopped
     environment:
       POSTGRES_DB: ethnograph
@@ -11,6 +11,7 @@ services:
       - "5432:5432"
     volumes:
       - pgdata:/var/lib/postgresql/data
+      - ./db/sql:/docker-entrypoint-initdb.d
 
 volumes:
   pgdata: