fix: broken "Authenticated Routes with Context" example link

[hugocostadev]

In the v1 and latest docs "Authenticated Routes with Context" in the Authenticated Routes Guide page is broken.

When I click goes to 404 page:

The correct link to the guide is: https://tanstack.com/router/v1/docs/framework/react/examples/authenticated-routes-context

The path was wrong, since all docs should be relative to docs/ path I fixed by changing

TO:

[Authenticated Routes with Context example](./examples/authenticated-routes-context)

FROM:

[Authenticated Routes with Context example](../../examples/authenticated-routes-context)