Feature Request: Add Default Editor Color Theme and Night mode in environment values

[j796160836]

I would like to ask new feature, which is add Default Editor Color Theme in environment values. I have checked the document, which is not exist this feature.

https://hackmd.io/c/codimd-documentation/%2F%40codimd%2Funderstanding-your-editor#18-Editor-Color-Theme https://hackmd.io/c/codimd-documentation/%2Fs%2Fcodimd-configuration

(Number 18. Editor Color Theme.)

I use E-ink devices (E-ink monitor, E-ink Android tablet), which need light theme but default editor is dark theme. I hope this feature will come true.