Update the link to refer the actual documentation

[EugenKon]

https://github.com/docker-library/docs/tree/487e4e632d0c0aaac7f70a1026b282ca9307c0df/postgres#postgres_password

[tianon]

Can you please be more specific? That link is accurate, and does discuss PGPASSWORD (and is even an actively supported version).

[EugenKon]

@tianon Sorry, how more specific could I be?

The most recent/actual is current: https://www.postgresql.org/docs/current/libpq-envars.html

[tianon]

Sure, but what's the problem with linking to the older release, especially when the top of the page we're linking to links directly to all the releases? I'd be very open to a PR against postgres/content.md in that docs repo you linked to update to https://www.postgresql.org/docs/17/libpq-envars.html, but I won't accept a change to link to /current/ because linking to non-versioned resources like that often leads us to dead links that are harder to track down than a versioned link (because at least there, the wayback machine can typically help us figure out what it was trying to link to so we can find the more recent analog when updating the link). Granted in this case (and most cases in the PG documentation), the page names are pretty stable, but the content isn't necessarily, so when we update, we want to make sure the updated page is still the appropriate place to find the right content we were intending to link to.

[EugenKon]

Yeah, that is the problem. I did not thought about that. Should it be better to provide both links: 17 and current? So new guys will aware that PostgreSQL has more recent documentation.

Or we can use current for the link and 17 for the link name like this: https://www.postgresql.org/docs/17/libpq-envars.html. Here 17 is displayed, but, actually, it is current.
If link occasionally not work user still have a chance to navigate to exact version manually by copy/pasting it.