Add an emoji dictionary

[kbenoit]

Possible sources:

• Emoji Sentiment Ranking 1.0. Data is also in the lexicons package.
• Emoticons: https://research.utwente.nl/files/5482763/sac13-senticon.pdf
• Multidimensional Lexicon of Emojis (MLE) https://pmc.ncbi.nlm.nih.gov/articles/PMC9231464/#TS1