Doc for optional humidity sensor in climate_ir component (#5161)

Co-authored-by: J. Nick Koston <nick@koston.org>
Co-authored-by: Jonathan Swoboda <154711427+swoboda1337@users.noreply.github.com>

Author: 3 people

content/components/climate/climate_ir.md

@@ -64,6 +64,8 @@ climate:
 
 - **sensor** (*Optional*, [ID](/guides/configuration-types#id)): The sensor that is used to measure the ambient
   temperature. This is only for reporting the current temperature in the frontend.
+- **humidity_sensor** (*Optional*, [ID](/guides/configuration-types#id)): The sensor that is used to measure the ambient
+  humidity. This is only for reporting the current humidity in the frontend.
 
 - **supports_cool** (*Optional*, boolean): Enables setting cooling mode for this climate device. Defaults to `true`.
 - **supports_heat** (*Optional*, boolean): Enables setting heating mode for this climate device. Defaults to `true`.