Add temperature unit option

[BSelene]

Hello👋, this is my first pull request ever.
I'm American so metric units are foreign to me. I added an option to display temperature in Fahrenheit.

• Added option to change between metric and imperial units in weather preference layout xml file.
• Updated strings xml file to include necessary strings.
• Updated P.kt file to generate URL based on new options and to store the preference.

[Domi04151309]

Thanks for your pull request 😄