Fix the mdx-components examples

[remcohaszing]

This is a duplicate of #64769, which was closed and locked based on false claims. Please see the comments there for context.

I opened this new PR as requested by @karlhorky.

[karlhorky]

@samcx Another MDX PR opened by Remco, one of the core contributors to MDX - would you be able to take a look?

cc @delbaoliveira @manovotny (original PR reviewers)

[karlhorky]

@manovotny I confirmed just now that the first argument components of useMDXComponents receives undefined - so this parameter can probably indeed be removed (unless I'm missing something):

mdx-components.tsx

export function useMDXComponents(components: MDXComponents): MDXComponents {
  console.log('components', components);
  return {
    ...components,

Output:

 ✓ Compiled in 208ms (490 modules)
components undefined