Review the guide: clarify database setup in step 11

[Hurricos]

This issue was going to be:

I just ran through this installer (pointing at a new host, mknc.laboratoryb.org), and did not see a prompt to select a database, but rather was forced into a prompt to use SQLite; image attached:

I paved the installation (removed volumes, images, etc), and tried again, with the same results.

I used git clean -f -x -d -n to find configuration files and probe them for database configuration, but didn't seem to find much other than what stack.yml was suggesting.

... but then I realized where the dropdown I needed to click was: