Add PostgreSQL configuration to .env.example and create Docker Swarm compose file

Author: mcqueide

.env.example

@@ -10,6 +10,8 @@ ENVIRONMENT=production
 POSTGRES_DB=people
 POSTGRES_USER_FILE=/run/secrets/db-user
 POSTGRES_PASSWORD_FILE=/run/secrets/db-password
+PGDATA=/var/lib/postgresql/data/pgdata
+POSTGRES_INITDB_ARGS=--encoding=UTF-8 --lc-collate=C --lc-ctype=C
 
 # ----------------------------------------------------------------------------
 # SPRING