[gimp-web/testing] Update GEGL section in GIMP 2.10.12 news.

[Jehan <jehanp src gnome org>]

commit 2ecc963744110a8c736c6cf6c63a87b55aecb6a8
Author: Jehan <jehan girinstud io>
Date:   Thu May 9 12:19:04 2019 +0900

    Update GEGL section in GIMP 2.10.12 news.
    
    As discussed with Pippin yesterday on IRC! :-)

 content/news/2019-05_GIMP-2.10.12_Released/index.md | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/content/news/2019-05_GIMP-2.10.12_Released/index.md 
b/content/news/2019-05_GIMP-2.10.12_Released/index.md
index 263c29a8..e66e535c 100644
--- a/content/news/2019-05_GIMP-2.10.12_Released/index.md
+++ b/content/news/2019-05_GIMP-2.10.12_Released/index.md
@@ -152,7 +152,12 @@ This code merge should hopefully happen soon enough!
 
 During this development span, GEGL 0.4.16 got released as well.
 
-TODO: tell more!
+The biggest user-visible change is probably the cubic sampler
+coefficient change, which used to produce smooth interpolation, suitable
+for some cases, but not as sharp as people would expect in most other
+cases. Now in all places where there is choice of interpolation (all
+transformation tools, Warp tool, etc.), the result with cubic has
+changed and produces now sharper result.
 
 # What's next