Ghostwriter is a multiplataform distraction-free Markdown editor. while I consider it a pretty good piece of software, it is still lacking a good variety of themes so users can avoid monotony when they feel like. Here I will collect my experimental themes, and you are invited to contribute yours.
Wereturtle, the developer of Ghostwriter, has now documented the Theme spec. You should read it there before you venture into theme-making. This is only a rough crash-course for beginners who just want to know where themes are and where they must put new themes.
If you have created some themes and don't want to create a repository of your own, feel free to add them here.