[expo-docs] Update docs to reflect that Expo.fonts.loadAsync actually returns a p…
[expo-docs] Update docs to reflect that Expo.fonts.loadAsync actually returns a p…

…romise.

Closes expo/expo-docs#262

exponentjs/exponent,exponentjs/exponent,exponent/exponent,exponent/exponent,exponentjs/exponent,exponent/exponent,exponentjs/exponent,exponentjs/exponent,exponent/exponent,exponentjs/exponent,exponent/exponent,exponent/exponent,exponentjs/exponent,exponent/exponent,exponent/exponent,exponentjs/exponent,exponent/exponent,exponentjs/exponent