Add option to specify output format

[ddzz]

Right now only an array of individual emojis is returned. There should be an option to concatenate these emojis into a single string.

[bmish]

Thanks for the suggestion.

I would agree with this suggestion if this was a CLI tool that simply printed the output and the user needed it to be in a convenient format.

However, since this tool is currently just a Node API / function, I think it's fine that we have one specified format that we return data in. The user can easily manipulate the resulting data using JS and turn it into whatever kind of string they need:

(await getEmojis(...)).map(result => result.join(''));

And it's better for us to return the data in separate pieces so that the user doesn't have to do any string parsing to access the individual emoji suggestions.