supplement Postgres listen example with a small chat example

[JockeM]

Closes #161

this is just a continuation of #2165 made by Stephen
i just took his chat implementation and fixed the readme and renamed the folder to chat

[abonander]

Can you also adjust the Github Actions workflow that tests this example?

You can just update the entry for the listen example: https://github.com/launchbadge/sqlx/blob/main/.github/workflows/examples.yml#L184-L196

Those entries are alphabetized to make it easier to navigate that file, so this should also be moved above Files (Setup) to keep things organized.

[abonander]

I think this is failing CI because it's expecting a TTY and not getting one, which is a real issue for automated testing. You'd have to specially allocate a TTY for the process, I think. But even so, it'd just sit there forever unless you actually sent it commands.

If you want to figure out how to automate TUI testing in CI, that's your prerogative, but I think it's good enough if we just check that it compiles. That should be noted in the README in case someone tries it and has problems with it.

That does make me hesitant to delete the listen example, however, as that was able to run in CI just fine. There's no reason not to have both, I think, since it's all handled in the same CI job anyway.

[JockeM]

Yeah rather not go for the testing in CI for this.
Should I take back the listen example?

[abonander]

Yeah just keeping the listen example is fine @JockeM, thanks.

[abonander]

One remaining nit + undeleting listen example.

[scd31]

Sorry for missing the request on the original PR! It slipped through on my end. Glad to see the changes were made and this was merged! (: