Add note about 3.1 download

Author: subramen

download.sh

@@ -3,6 +3,10 @@
 # Copyright (c) Meta Platforms, Inc. and affiliates.
 # This software may be used and distributed according to the terms of the Llama 2 Community License Agreement.
 
+####
+## NOTE: For downloading Llama 3.1 please refer to https://github.com/meta-llama/llama-models/tree/main/models/llama3_1#download
+####
+
 set -e
 
 read -p "Enter the URL from email: " PRESIGNED_URL