Fix overflow issue in Demo element

Author: TheZoker

Diff for: src/components/common/Demo.js

@@ -60,6 +60,7 @@ const TabsWrapper = styled('div')({
 });
 
 const TabsContainer = styled(Tabs)({
+  overflow: 'auto',
   '& li:first-child': {
     marginRight: 'auto',
   },