Talking about Markdown's CodeMirror theme update

[Daeraxa]

@lashiec1987

Note that the below is incomplete; I only changed the colors for the lists and a lot of this looks pretty terrible in dark mode as-is.

In case you do want the rest I did have a go at creating the css to restore the rest of the dark theme a while ago - Dark theme syntax highlighting - #4 by Daeraxa