Update A parameters (#755)

Author: ccutch

src/routes/solid-router/getting-started/linking-routes.mdx

@@ -66,7 +66,7 @@ In addition, the `<A>` component has an `active` class if its `href` matches the
 This provides the link with a CSS class to show when the link is active or inactive.
 
 ```jsx
-<A href="/users" active="underlined" inactive="default">
+<A href="/users" activeClass="underlined" inactiveClass="default">
 	Users
 </A>
 ```