fix(list-group): include item index on template function argument list

Author: assisrafael

demo/ListGroupExamples.jsx

@@ -28,8 +28,9 @@ export function ListGroupExamples() {
         <h1 className="h4">Simple list group</h1>
         <ListGroup
           items={items}
-          template={(item) => (
+          template={(item, index) => (
             <>
+              <em>{index + 1} </em>
               <strong>{item.title}</strong> <br />
               {item.description}
             </>

src/list-group/ListGroup.jsx

@@ -13,7 +13,7 @@ export function ListGroup({ items, active, linked, bordered, horizontal, templat
       linked={linked}
       onSelect={onSelect}
     >
-      {template(item)}
+      {template(item, index)}
     </ListGroupItem>
   ));