feat - set async workers (#452)

## Changes
- set uvicorn workers, default 1

Author: Ilevk

scripts/app-start.sh

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 
 export PORT=${PORT:-8000}
+export WORKERS=${WORKERS:-1}
 
 NUMREGEX="^[0-9]+$"
 GRACEFUL_SHUTDOWN_PERIOD_SECONDS=3600
@@ -25,7 +26,8 @@ ${OPTIONAL_TIMEOUT} \
     uvicorn prepline_general.api.app:app \
     --log-config logger_config.yaml \
     --host 0.0.0.0 \
-    --port "$PORT"
+    --port "$PORT" \
+    --workers "$WORKERS" \
 
 echo "Server was shutdown"
 [ -n "$MAX_LIFETIME_SECONDS" ] && echo "Reached timeout of $MAX_LIFETIME_SECONDS seconds"