doc PG 18 relnotes: adjust wording of initdb item 48814415d5a

Bruce Momjian <bruce@momjian.us>

Commit: 37e5f0b61fa8aad82a0b06438ed95c282ace994a
Author: Bruce Momjian <bruce@momjian.us>
Date: 2025-06-07T15:06:47Z
Releases: 18.0
doc PG 18 relnotes:  adjust wording of initdb item 48814415d5a

And move to the top of the incompatibility list.  This will impact users
more than any other incompatibility item because of pg_upgrade.

Files

PathChange+/−
doc/src/sgml/release-18.sgml modified +18 −21

Documentation touched