docs(readme): update roadmap about styling config

Author: tharropoulos

README.md

@@ -246,7 +246,7 @@ All contributions are welcome! If you're planning a significant change or you're
 
 ## Roadmap
 
-- Add support for more style options like text color and background color
+- ~~Add support for more style options like text color and background color~~ ✅ **Done!**
 - ~~Allow choosing from any glamour themes~~ ✅ **Done!**
 - ~~Support for custom JSON theme files~~ ✅ **Done!**
 - Create grid-based slide layouts with transitions for each pane