[GreenText] Text is highlighted incorrectly when using multi-line quotes

[MMK21Hub]

When a message contains a multi-line markdown quote (>>>), the entirety of the first line of the quote is coloured green, and the first few characters of the second line in the quote are also coloured green.

This is inconsistent with single-line quotes (>).

To reproduce

Send a message containing a multi-line markdown quote:

>>> Hello
Good evening!

Screenshots