add build lambdas script to accompany the quickstart guide

deployment/build-lambdas.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+
+BASE_DIR="lambdas"
+LAMBDA_DIRS=("presign" "list" "resize")
+
+for dir in "${LAMBDA_DIRS[@]}"; do
+    LAMBDA_PATH="$BASE_DIR/$dir"
+    echo "Zipping Lambda function in $LAMBDA_PATH..."
+    if [ -d "$LAMBDA_PATH" ]; then
+        zip -r "$LAMBDA_PATH/lambda.zip" "$LAMBDA_PATH"/*
+    else
+        echo "Directory $LAMBDA_PATH not found!"
+        exit 1
+    fi
+done