Variables are {dotted.key} placeholders that flanker replaces with live data
when a message is sent. Use them anywhere you customise a message: welcome and
leave messages, embeds, autoresponders, tags, boost messages and more.
For example, a welcome message of:
Welcome {user.mention} to {guild.name}! You are member #{guild.count}.
is sent as Welcome @name to My Server! You are member #1234.