Change single-column mode to scroll the whole page (#11359)

Fix #10840

app/javascript/mastodon/features/public_timeline/index.js

@@ -126,6 +126,7 @@ class PublicTimeline extends React.PureComponent {
           scrollKey={`public_timeline-${columnId}`}
           emptyMessage={<FormattedMessage id='empty_column.public' defaultMessage='There is nothing here! Write something publicly, or manually follow users from other servers to fill it up' />}
           shouldUpdateScroll={shouldUpdateScroll}
+          bindToDocument={!multiColumn}
         />
       </Column>
     );