Improve the docs 404 page

[djwfyi]

Is your feature request related to a problem? Please describe. The 404 page does not contain the site header or any other context helpful clues for an end user. The home link goes back to docs.min.io, which is the legacy docs and may not be what a user needs to go back to.

Describe the solution you'd like The 404 page should have the same top navigation bar as the rest of the docs. Ideally, it would also provide the left navigation bar and be sensitive to which portion of the docs the user is in (legacy vs. VMWare vs. Baremetal, etc.)

Describe alternatives you've considered N/A

Additional context I have found a few documentation links from the Console that are resulting in 404s.