Add detailed documentation on award emojis
Some questions to be answered:
- Why should one use the award emojis? What are the use cases?
- Are they counted as comments?
- Can I sort the issues/MRs based on emoji count?
- Is there an API for award emojis? Namely, can one find the number of award emojis with an API query?
- What are the differences between thumbs(up|down) emojis and all the other ones?