[gimp] NEWS: mention newly added on-canvas gradient editing

[Alexandre Prokoudine <aprokoudine src gnome org>]

commit 695b6ed260d9ee2b202c578421864434993a3a9b
Author: Alexandre Prokoudine <alexandre prokoudine gmail com>
Date:   Tue Oct 10 09:35:52 2017 +0300

    NEWS: mention newly added on-canvas gradient editing

 NEWS |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)
---
diff --git a/NEWS b/NEWS
index feb8528..d9936da 100644
--- a/NEWS
+++ b/NEWS
@@ -27,6 +27,17 @@ Core:
     is not installed for the GUI language (alongside the possibility to
     read online) and the choice can be edited in preferences.
 
+Tools:
+
+  - Blend tool now features on-canvas gradient editing: adding, shifting,
+    removing color stops, shifting midpoints and converting them to color
+    stops, assignging colors to color stops, changing blending type
+    for midpoints. Additional options: 'Instant mode' (active before you
+    start blending) to support the old workflow where you can't edit color
+    stops before applying the gradient fill, and 'Modify active gradient'
+    which allows changing user-writable gradients directly rather than
+    creating copies of them.
+
 Color management:
 
   - Use babl to convert between profiles if possible.