doc: improve PG 14 relnote item about adding btree pages to FSM

Bruce Momjian <bruce@momjian.us>

Commit: 049d3617a3bedb2a1d97d1621f36c861f52269a7
Author: Bruce Momjian <bruce@momjian.us>
Date: 2021-07-08T16:27:55Z
Releases: 14.0
doc:  improve PG 14 relnote item about adding btree pages to FSM

Wording confirmed by Peter Geoghegan.

Backpatch-through: 14 only

Files

PathChange+/−
doc/src/sgml/release-14.sgml modified +3 −3

Documentation touched