Just for fun: Postgres 20?

Hackers,

    Musing some other date-related things I stumbled upon the thought
that naming the upcoming release PostgreSQL 20 might be preferrable to
the current/expected "PostgreSQL 13".

Cons:

 * Discontinuity in versions. 12 -> 20.  Now that we have the precedent
of 9.6 -> 10 (for very good reasons, I think), this is probably a minor
issue... Mostly the inconvenience of having to add tests for the skipped
versions, I believe.

    ¿any others that I don't know about?

Pros:

 * Simplified supportability assessment:  PostgreSQL 20, released in
2020, would be supported until the release of PostgreSQL 25 (late 2025
if release cadence is kept as today). Simple and straightforward.

 * We avoid users skipping the release altogether due to superstition
or analogous reasons ---might be a major issue in some cultures---.
Postgres 13 would be certainly skipped in production in some
environments that I know about o_0

Nothing really important, I guess. I think of it as a thought experiment
mostly, but might spark some ultimate useful debate.

Thanks,

    / J.L.