[expo-docs] Emphasising only one option should be chosen.
[expo-docs] Emphasising only one option should be chosen.

Emphasising only one option should be chosen  to make this clearer.

Closes expo/expo-docs#350

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