Add Error Handling for Missing lib Directory in CI (publish) Workflow (#393)

* add 'set -e' to libdoc.sh for better error handling
* enhance publish.yml workflow with 'set -e' for error handling in CI script
* add 'set -x' to libdoc.sh for command tracing

libdoc.sh

@@ -15,6 +15,9 @@
 # User's Guide.
 #
 
+set -x
+set -e
+
 if [ $# -eq 0 ]; then
   echo "Usage: $0 { branch | version | 'release' | 'all' }..."
   echo