scritps : add helper script to get hellaswag data in txt format

scripts/get-hellaswag.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+wget https://raw.githubusercontent.com/klosax/hellaswag_text_data/main/hellaswag_val_full.txt
+
+echo "Usage:"
+echo ""
+echo "  ./perplexity --hellaswag --hellaswag-tasks N -f hellaswag_val_full.txt -m modelfile.gguf"
+echo ""
+
+exit 0