[gimp-web] Update 2.99.4 news.

[Jehan <jehanp src gnome org>]

commit 3fdb1551d67e24e86d854ac9d39d37ad7d39cc3c
Author: Jehan <jehan girinstud io>
Date:   Sat Dec 19 19:49:44 2020 +0100

    Update 2.99.4 news.

 .../2020/2020-12_GIMP-2.99.4_Released/index.md     | 70 +++++++++++++++++++++-
 1 file changed, 68 insertions(+), 2 deletions(-)
---
diff --git a/content/news/2020/2020-12_GIMP-2.99.4_Released/index.md 
b/content/news/2020/2020-12_GIMP-2.99.4_Released/index.md
index c95b0ab6..8d11479d 100644
--- a/content/news/2020/2020-12_GIMP-2.99.4_Released/index.md
+++ b/content/news/2020/2020-12_GIMP-2.99.4_Released/index.md
@@ -58,7 +58,51 @@ discovery:
 
 ## Multi-layer selection
 
-FIXME
+Multi-item selection in the `Layers` dockable comes with a few generic
+key combinations, common multiple selection interactions such as:
+`Shift-click` for range selection or `Ctrl-click` for selection
+modification. These interactions clashed with some features we had on
+layer and mask thumbnails. For instance one could end up modifying a
+selection and in the same time create or remove masks by mistake.
+
+Since the multiple selection feature is just too important and these
+generic interactions so well established across software (hence their
+removal or replacement not even a question), here are the design choices
+taken:
+
+* No special click features in the `Layers` dockable should be based
+  only on `Shift`, `Ctrl` or `Shift-Ctrl` modifiers, but it could
+  include these if any additional modifier (e.g. `Alt`) comes to play.
+* We moved any existing feature which didn't follow such rule to a
+  `Alt+` combination, as said additional modifier.
+* If all modifier combinations are taken, we removed click-features
+  based mostly on seniority.
+* Actions are now based on exact modifier combinations to avoid feature
+  clashes (e.g. `Ctrl-click` should not trigger both the `Ctrl-click`
+  and simple `click` actions).
+* Actions done when clicking a thumbnail with modifiers do not change
+  the selection anymore and will now operate on the clicked layer or
+  mask, not on selected layers/masks. This makes these actions more
+  useful as they are not redundant anymore.
+
+The concrete consequential changes are as follow:
+
+* `Ctrl-click` on a mask thumbnail to enable/disable it is changed to
+  `Alt-Ctrl-click`. The other mask action, `Alt-click` for showing
+  the mask, stays the same.
+* `Shift-click` and `Ctrl-click` actions on a layer thumbnail to
+  respectively add (with last used values) or remove a layer mask have
+  been removed. Indeed all `Alt+` combinations are already taken on
+  layer thumbnails (for "*Alpha to Selection*", "*Add Alpha to
+  Selection*", "*Subtract Alpha from Selection*" and "*Intersect Alpha
+  with Selection*", respectively on `Alt-click`, `Alt-Shift-click`,
+  `Alt-Ctrl-click` and `Alt-Shift-Ctrl-click`; we also took the
+  opportunity to improve the *Undo* labels for these actions, improving
+  discoverability on random clicks) and these "*Add/Remove mask*"
+  actions were much newer (2.10.0) anyway.
+* Thumbnail popups on long click do not happen anymore when any modifier
+  is hold, hence removing a distraction when this was obvioulsy not what
+  we were looking for.
 
 ## Input Devices dialog
 
@@ -136,7 +180,29 @@ understandable hence useful to more people.
 
 ## Better device defaults
 
-FIXME.
+As explained in the 2.99.2 release, GIMP 3 has a much better input
+device detection as well as hotplug detection. So it became much more
+important to provide reasonable defaults when a new device is detected
+so that people are able to immediately check it works correctly.
+In particular for graphics tablets, people want to test immediately that
+pressure is supported.
+
+For these reasons, here are the tools enabled by default the first time
+you plug a device:
+
+* Pen devices (tablet styluses main input): *Paintbrush* tool;
+* Eraser devices (tablet styluses back input): *Eraser* tool;
+* Touch screens (finger): *Smudge* tool;
+* All other devices: *Paintbrush* tool.
+
+Moreover the default dynamics when a new device is plugged is now
+"*Pressure Size*", i.e. that the brush size will increase when pressing
+harder.
+
+This should make the first-time experience of GIMP much more enjoyable
+for people using graphics tablets, as they can directly start to paint
+on canvas without having first to understand all the inner-settings of
+GIMP paint system (based on the combination of brush and dynamics).
 
 # New experimental Paint Select tool