The readme explains how to sync existing pages, but not how to create new ones.
Start the local env (not technically necessary, build:patterns will start it, but doing this first ensures your env is working if you haven't run it recently)
Add to manifest.json
Add to the allowedlist in theme-switcher.php
Run build:patterns
Creates the pattern synced from the remote page content
Creates the page template which references the new pattern
If necessary, update the header & footer style in the page template (for a white, black, or blue background)
The readme explains how to sync existing pages, but not how to create new ones.
build:patterns