Support props.children

[KVinS]

Hello. Why not implement text support between tags?
<SelectableText>Value</SelectableText>
It is necessary for compatibility with react-native-htmlview eg
I had to make a wrapper. Lol

export const MySelectableText = (props) => {
    return (
        <SelectableText {...props} value={props.children}/>
    );
}

[nsantacruz]

See my pull request (#53) which allows for more natural support with react-native-htmlview by allowing you to pass in an alternate TextComponent.