In Depth Tutorial

# Summary

Now that the Twitter tutorial has been removed from the Admin UI, we should replace it with a tutorial that makes sense for our use case and guides users through a series of CrateDB features.

# Detail

Commit 1338d7acedf435d2dcb8217b778897ffe0dad1bd removed the old Twitter tutorial, since over time it has become flaky and not fit for purpose. One problem is that the Twitter tutorial was not much a tutorial at all. a convienient way of getting a table with some data to play around with, sure; but as an actual tutorial to teach users about CrateDB it was quite lacking.

My proposal would be to add a multi-stage, interactive tutorial covering basic CrateDB concepts such as:

- Table creation, insertion, deletion, and basic querying.
- Table partitioning.
- Generated columns.
- Using CrateDB functions.

It could also be useful to cover more advanced topics like:

- Sharding
- UDFs
- User/Permission management
- Setting/viewing cluster options