Tutorial order for the docs

Currently, there’s no sequencing or even a basic order for the tutorials that a new user can follow. The only tidbit that tells users what to do next are in the Next steps sections, specifically the one at the bottom of the [Quickstart (local)](https://druid.apache.org/docs/latest/tutorials/index.html#next-steps) page.

There should be an index page that lays out a suggested tutorial sequence for a new user to follow so that they learn about Druid in a logical progression.

Once this sequence is laid out, the left nav for tutorials should also be updated to reflect the order.

Start with the Tutorials index and the Quickstart (local) page, especially its Next steps section, then review the existing tutorial list and left navigation. Define a logical progression for new users, add an index page describing that sequence, and update the tutorial navigation to match it.

Written by the indexing model from the issue text.