fix(RangeDatePicker): add component export (#62)

Author: korvin89

src/components/index.ts

@@ -2,6 +2,7 @@ export * from './Calendar';
 export * from './RangeCalendar';
 export * from './DateField';
 export * from './DatePicker';
+export * from './RangeDatePicker';
 export * from './RelativeDateField';
 export * from './RelativeDatePicker';
 export * from './RangeDateField';