[gimp/gimp-2-10] Update NEWS

[Alexandre Prokoudine <aprokoudine src gnome org>]

commit d20efd357a2370f2c3eefe08ad6a1b675a33c747
Author: Alexandre Prokoudine <alexandre prokoudine gmail com>
Date:   Thu Nov 29 00:09:02 2018 +0300

    Update NEWS

 NEWS | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/NEWS b/NEWS
index e793e07498..b0bc0966d7 100644
--- a/NEWS
+++ b/NEWS
@@ -26,6 +26,9 @@ Core:
   - Pass the GEGL tile-cache size, swap path, and thread-count to plug-ins
     as part of their config, and have libgimp set the plug-in's GeglConfig
     accordingly upon initialization.
+  - Layer groups are now rendered in bigger chunks rather than tile-by-tile
+    (which used to pretty much eliminate multithreading for groups), which
+    improves the rendering speed.
 
 User interface:
 
@@ -53,7 +56,7 @@ Installers:
 
 Translations:
 
-  - Czech, Polish, Ukrainian.
+  - Czech, Italian, Polish, Spanish, Ukrainian.
 
 Overview of Changes from GIMP 2.10.6 to GIMP 2.10.8
 ===================================================