fix readme

README.md

@@ -26,10 +26,10 @@
 
 # TODO
 
-- [] Better UI
+- [ ] Better UI
-- [] Library Model
+- [ ] Library Model
-- [] Notification Model
+- [ ] Notification Model
-- [] Calendar
+- [ ] Calendar
-- [] Parent Model
+- [ ] Parent Model
-- [] Study Material
+- [ ] Study Material
-- [] Routine
+- [ ] Routine