Fix minor syntax (#76)

exercises/02.routing/01.problem.routes/README.mdx

@@ -185,7 +185,7 @@ export default function Child() {
 
 With that, when you navigate to `/parent/child`, you'll see "Parent" above
 "Child". If we swap the `<h1>` and `<Outlet />` in the parent, then the child
-will be above the parent. The parent gets to decide where it's child goes.
+will be above the parent. The parent gets to decide where its child goes.
 
 🐨 So go ahead and open the <InlineFile file="app/routes/users+/kody_+/notes.tsx" line={4} column={99} /> file and
 get the `<Outlet />` component from `@remix-run/react`, then render it below the