docker-compose.yml: Add PostGIS envvar to create database on initial setup.

docker/docker-compose.yml

@@ -29,6 +29,7 @@ services:
     environment:
       POSTGRES_USER: postgres
       POSTGRES_PASSWORD: password
+      POSTGRES_DB: dawarich_development
     restart: always
     healthcheck:
       test: [ "CMD-SHELL", "pg_isready -U postgres -d dawarich_development" ]