Fix markdown links on Next.js page

Author: DmitryScaletta

docs/usage/nextjs.mdx

@@ -386,7 +386,7 @@ The App Router has four seperate caches including `fetch` request and route cach
 export const dynamic = 'force-dynamic'
 ```
 
-After a mutation you should also invalidate the cache by calling (`revalidatePath`)[https://nextjs.org/docs/app/api-reference/functions/revalidatePath] or (`revalidateTag`)[https://nextjs.org/docs/app/api-reference/functions/revalidateTag] as appropriate.
+After a mutation you should also invalidate the cache by calling [`revalidatePath`](https://nextjs.org/docs/app/api-reference/functions/revalidatePath) or [`revalidateTag`](https://nextjs.org/docs/app/api-reference/functions/revalidateTag) as appropriate.
 
 ### RTK Query