Full changelog: v0.5.4...v1.0.0 - https://github.com/getumbrel/umbrel/compare/v0.5.4...v1.0.0?ref=nobsbitcoin.com
You can read more about the v1.0 update in the initial announcement here. https://blog.getumbrel.com/introducing-umbrelos-1-0-9397458c9862