Adjustments in the TemperatureConversion

[DevGuiRocha]

Adjustments in the calculation of the Fahrenheit temperature, where the last sum of 273.15 was not achieved; Adjustments in the description of the kelvin_to_fahrenheit function, where the calculation description was incorrect, as it describes the formula for calculating fahrenheit to kelvin; Removal of duplicate round, where it was called twice in the last functions.