doc PG 17 relnote: adjust "SLRU cache sizes to be configured"

Add Álvaro Herrera as additional item author.

Reported-by: Álvaro Herrera

Discussion: https://postgr.es/m/202405231122.zew2gncy63fo@alvherre.pgsql

Author: Álvaro Herrera

Backpatch-through: master

doc/src/sgml/release-17.sgml

@@ -906,12 +906,12 @@ Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
 
 <listitem>
 <para>
-Allow the SLRU cache sizes to be configured (Andrey Borodin, Dilip Kumar)
+Allow the SLRU cache sizes to be configured (Andrey Borodin, Dilip Kumar, Alvaro Herrera)
 </para>
 
 <para>
 The new server variables are commit_timestamp_buffers, multixact_member_buffers, multixact_offset_buffers, notify_buffers, serializable_buffers, subtransaction_buffers, and
-transaction_buffers.
+transaction_buffers. commit_timestamp_buffers, transaction_buffers and subtransaction_buffers scale up automatically with shared_buffers.
 </para>
 </listitem>