Add more notes on what's going on there

examples/develop-prestashop/init-scripts/build-assets.sh

@@ -1,7 +1,21 @@
 #!/bin/sh
 set -eu
 
-echo "* Build PrestaShop assets..."
+echo "* Download composer dependencies..."
 make composer
+
+echo "* Build PrestaShop assets..."
+# Disclaimer: it seems that the PrestaShop front-end assets currently require
+#   to install Node.js dependencies globally. This is a bad pattern, which would
+#   require this script to be run as root.
+#
+# As an alternative, we propose this NPM_PREFIX_DIR hack suggestion, which could
+# eventually help to avoid running init-scripts as root in the future
+#
+NPM_PREFIX_DIR=/tmp/npm
+mkdir -p $NPM_PREFIX_DIR
+npm prefix -g $NPM_PREFIX_DIR
+export PATH="$PATH:$NPM_PREFIX_DIR/bin"
 make assets
-echo "* Assets built!"
+
+echo "✅ Assets built!"