run migrator in the background by default

bin/migrate_iaids

@@ -1,15 +1,14 @@
 #!/bin/bash
 set -e
 
-# WARN: This script can run for a long time. Running this within a
-# screen session or as a background process is strongly recommended
-
 # INFO: Usage: bin/migrate_iaids path/to/audit_json
 # See bin/ia_to_s3_migrator
 
+echo 'Starting IAID migration in the background'
+
 STAGE_ENV=production docker compose run \
   --rm \
   --remove-orphans \
   --volume /store/tmp/fast-tmp:/store/tmp/fast-tmp \
   web \
-  "bundle exec bin/ia_to_s3_migrator $1"
+  "bundle exec bin/ia_to_s3_migrator $1" &