doc: add Heikki to PG 12 release note btree item

Reported-by: Peter Geoghegan
Discussion: https://postgr.es/m/CAH2-WzkrX-aA7d3OYtQT+8Mspq+tU5vwuVz=FTzMH3CdrSyprA@mail.gmail.com

diff --git a/doc/src/sgml/release-12.sgml b/doc/src/sgml/release-12.sgml
index aa3ed455f8b853e24255cb33b43fe0b0489e863d..eb4f8998cf9a91d2bf744ab816da9912a7c273b9 100644 (file)
--- a/doc/src/sgml/release-12.sgml
+++ b/doc/src/sgml/release-12.sgml
@@ -632,7 +632,7 @@ Author: Peter Geoghegan <pg@bowt.ie>
 -->
 
 <para>
-Have new btree indexes sort duplicate index entries in heap-storage order (Peter Geoghegan)
+Have new btree indexes sort duplicate index entries in heap-storage order (Peter Geoghegan, Heikki Linnakangas)
 </para>
 
 <para>