patch 9.1.0915: GVim: default font size a bit too small

Problem:  GVim: default font size a bit too small
Solution: increase guifont size to 12 pt on GTK builds
          of gVim (matveyt).

fixes: #16172
closes: #16178

Signed-off-by: matveyt <matthewtarasov@yandex.ru>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/version9.txt b/runtime/doc/version9.txt
index 312a1c2..7691142 100644
--- a/runtime/doc/version9.txt
+++ b/runtime/doc/version9.txt
@@ -41615,6 +41615,8 @@
   and removed from |defaults.vim|
 - the completed word and completion type are provided when handling the
   |CompleteDone| autocommand in the |v:event| dictionary
+- the default fontsize for the GTK builds of Vim (Windows and Unix) has been
+  increased to 12pt to accomodate modern high-dpi monitors
 
 							*added-9.2*
 Added ~