Thread: pgsql: docs: Add acronym and glossary entries for I/O and AIO

docs: Add acronym and glossary entries for I/O and AIO

These are fairly basic, but better than nothing.  While there are several
opportunities to link to these entries, this patch does not add any. They will
however be referenced by future patches.

Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/20250326183102.92.nmisch@google.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/46250cdcb037e302ec5f0734ea0d06e2d21193e0

Modified Files
--------------
doc/src/sgml/acronyms.sgml | 18 ++++++++++++++++++
doc/src/sgml/glossary.sgml | 39 +++++++++++++++++++++++++++++++++++++++
2 files changed, 57 insertions(+)