New Message Markdown For Suggesting/Running Slash Commands

[deniz-blue]

It's like how we have unix timestamp styling like <t:1618953630>, but for slash commands. It could either run the slash command when clicked or suggest the slash command by typing it on the chatbox.

This can be used in stuff like help menus for more accessibility and less time typing the correct slash command

[Luc1412]

Seems like a duplicate of #3288