Add Simple Dark Theme

[Flower Ornament]

I published a simple dark theme here based on logseq-bonofix-theme. It's not up to the quality level of other themes here, but I thought I'd mention it in case you want to include it:

https://github.com/flowerornament/logseq-simple-dark-theme/

[Junyi Du]

Pretty cool!
Can you open a PR to add the line?