Add "embed" output format to 8-Ball messages

[ZeroKnight]

For protocols that support it, it would look nice to display the 8-Ball reading in an embed, e.g. Discord.

• Use Green/Gray/Red accent coloring for Positive/Neutral/Negative responses
• Add an 🎱 icon (maybe with some magic ✨)
• Place ZeroBot's intro as the "description"
• Place ZeroBot's outro as text following the embed (i.e. the message body)