fix: launch trainer from extracted archive

start.sh

@@ -1,7 +1,12 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-trainer_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+if [[ -f "$script_dir/scripts/jrich-wakeword-trainer" ]]; then
+  trainer_root="$script_dir"
+else
+  trainer_root="$(cd "$script_dir/.." && pwd)"
+fi
 
 if ! command -v python3 >/dev/null 2>&1; then
   echo "Python 3.11 or newer is required. Install it, then run this file again." >&2