wait for db ready before starting backend

run.sh

 #!/usr/bin/env bash
 
 docker-compose build
-docker-compose up -d
+docker-compose up -d db
+
+echo 'Waiting for database to be ready...'
+until [ $(docker-compose exec db psql -U postgres -c "\q" | wc -l) -eq 0 ]; do
+    printf '.'
+    sleep 1
+done
+
+docker-compose up -d backend