Hi Jamie,
Browsable schemas for the stable branches are now available here:
https://dev.totaralms.com/docs/schemaspy/totara-2.4/
https://dev.totaralms.com/docs/schemaspy/totara-2.2/
https://dev.totaralms.com/docs/schemaspy/totara-1.1/
https://dev.totaralms.com/docs/schemaspy/totara-1.0/
Note that these are generated nightly from HEAD so might actually be slightly ahead of the actual releases.
Simon