Adding roo_prefs to repositories.txt (#4947)

Author: dejwk

repositories.txt

@@ -1709,6 +1709,7 @@ https://github.com/dejwk/roo_flags
 https://github.com/dejwk/roo_icons
 https://github.com/dejwk/roo_logging
 https://github.com/dejwk/roo_material_icons
+https://github.com/dejwk/roo_prefs
 https://github.com/dejwk/roo_scheduler
 https://github.com/dejwk/roo_time
 https://github.com/delta-G/EventLinkInterrupt