This function starts by looking for exact matches in emoji_name. If none is
found in emoji_name then it looks in emoji_keyword. emoji_keyword can
produce more then 1 matches, which will lead to one being returned at random.
Usage
emoji(keyword)
Arguments
keyword
Character, either name or keyword. If more than one emoji has
the specified keyword, will pick one at random.
Details
This function isn't vectorized and will thus only work with 1 keyword at a
time.