fix(docs): add missing semicolon (#11850)

Author: princemaple

src/material-examples/table-sticky-footer/table-sticky-footer-example.html

@@ -16,6 +16,6 @@
 
     <tr mat-header-row *matHeaderRowDef="displayedColumns"></tr>
     <tr mat-row *matRowDef="let row; columns: displayedColumns;"></tr>
-    <tr mat-footer-row *matFooterRowDef="displayedColumns sticky: true"></tr>
+    <tr mat-footer-row *matFooterRowDef="displayedColumns; sticky: true"></tr>
   </table>
-</div>
+</div>