smartport batt sensor: update docs/Settings.md

Author: functionpointer

docs/Settings.md

@@ -6504,7 +6504,7 @@ Maximum voltage per cell in 0.01V units, default is 4.20V
 
 ### vbat_meter_type
 
-Vbat voltage source. Possible values: `NONE`, `ADC`, `ESC`. `ESC` required ESC telemetry enebled and running
+Vbat voltage source. Possible values: `NONE`, `ADC`, `SMARTPORT`, `ESC`. `ESC` requires ESC telemetry enabled and running. `SMARTPORT` requires SmartPort Master enabled and running.
 
 | Default | Min | Max |
 | --- | --- | --- |