The bit about the matrix-make-user-admin script was messed up (it wasn't actually a code block so the "<username>" was hidden). For me at least it seems like the ``` syntax is much harder to accidentally mess up.
Prerequisites
Configuring your DNS server
Getting this playbook’s source code
Configuring the playbook
Installing
Registering users
Updating users passwords
Configuring service discovery via .well-known
Maintenance / checking if services work
Maintenance / upgrading services
Maintenance / PostgreSQL
Maintenance and Troubleshooting
Uninstalling