Contributor Training: Supporting users using `ddev debug test` and other tools

We don't have to do an enormous amount of support, but people occasionally have obscure problems, and they often don't describe their environment well enough to help us help them.

That's where the command `ddev debug test` comes in. It allows people to run a full diagnostic that can demonstrate exactly what problems DDEV may encounter.

We'll look at this and other ways to help people in Discord or the issue queue and Stack Overflow. Interpreting the output of `ddev debug test` may be a bit of an art.