edited the "hold mode" statement to be preset_mode. Changed the 'off' preset_mode to 'none', and added the 'away' preset_mode. Confusing to a relatively new user since hold mode isn't in the states dev tools or general climate documentation, and 'off' isn't a valid preset_mode
Add ColorTouch T7850 as a supported/tested thermostat as well as list the currently tested firmware version VH6.79. Add a note how to enable local API.