Update SideMenu.tsx #87

Signed-off-by: Joseph Garrone <joseph.garrone.gj@gmail.com>

Author: garronej

src/SideMenu.tsx

@@ -25,7 +25,7 @@ export type SideMenuProps = {
 };
 
 export namespace SideMenuProps {
-    export type Item = Item.Link & Item.SubMenu;
+    export type Item = Item.Link | Item.SubMenu;
 
     export namespace Item {
         type Common = {