Add Additional Markdown Rendering Functionality

There hasn't been a similar post (that I could find) within the past 2 years, so let's try this again in 2023 to see if we can make a positive change early this year.

Currently, Discord text messages will render simple/basic Markdown like: bold or italicized text, quotes, in-line code, code blocks... and that's about it.

Being in a position as both the pioneer and the leader of this market, supporting all features of the Basic Syntax for Markdown should be the minimum acceptable product. Here's a link to the official spec: https://www.markdownguide.org/basic-syntax/

Immediately, I think about how useful headers would be, how often I try to build nested lists in Discord messages or how I've seen so many messages that would look dramatically better as a table.

Please bring us up to speed, Discord!