Some improvements to CompatRoute documentation in the migration guide

[kirkobyte]

The "1) Render CompatRoute elements inside of Switch" section of the migration guide has a few things which I think might need to be clarified.

Using element with CompatRoute

The migration guide recommends to make this change to fix optional params in paths:

- <Route path="/one/:two?" element={Comp} />
+ <CompatRoute path="/one/:two" element={Comp} />
+ <CompatRoute path="/one" element={Comp} />

It uses element to render the path children. If I understand correctly, those props are eventually ending up on a V5 Route, which doesn't support element as a prop. So it might make sense to change the example to use `

Warning on path for CompatRouter may need to warn against arrays in path

⚠️ You can't use regular expressions or optional params in v6 route paths. Instead, repeat the route with the extra params/regex patterns you're trying to match.

The previous Route also used to support arrays as a path parameter:

<Route path={['/path-one', '/path-two']} render={/* Component here */}/>

Doing this with CompatRoute has bad results since it will have /* added to the V6 route, making the path /path-one,/path-two,/*

react-router/packages/react-router-dom-v5-compat/lib/components.tsx

Lines 16 to 24 in 334589b

	export function CompatRoute(props: any) {
	let { path } = props;
	if (!props.exact) path += "/*";
	return (
	<Routes>
	<Route path={path} element={<RouteV5 {...props} />} />
	</Routes>
	);
	}

[kirkobyte]

cc @ryanflorence