Merge pull request #411 from jasperfirecai2/fix-cnavgroup

fix(CNavGroup): set default `height` state to 0

Author: mrholek

packages/coreui-react/src/components/nav/CNavGroup.tsx

@@ -58,7 +58,7 @@ export const CNavGroup: PolymorphicRefForwardingComponent<'li', CNavGroupProps>
   HTMLDivElement | HTMLLIElement,
   CNavGroupProps
 >(({ children, as: Component = 'li', className, compact, idx, toggler, visible, ...rest }, ref) => {
-  const [height, setHeight] = useState<number | string>()
+  const [height, setHeight] = useState<number | string>(0)
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   const navItemsRef = useRef<any>(null)