Please consider update usage of PostgreSQL database to containerized image and started by podman or docker. The following part could be improved.

• In current state there is outdated link to download a standalone database. I get 404 error code when try to use provided link in the Readme. Please consider usage podman/docker image with postgress.
• Manual Creating a module.xml with PostgreSQL configuration is not good practice. Consider update it to CLI configuration like in case of the ejb-txt-remote-call 
• In chapter "Configure Server1 to use PostgreSQL" is used same command "$WILDFLY_HOME_1/bin/jboss-cli.sh --connect --file=configure-jts-transactions.cli" as in chapter "Configure the First Server". Here I am expecting a CLI script with data source configuration instead of transaction configuration.