[gnome-devel-docs/wip/jimmac/appicon-update] icons: elaborate on shadows

[Jakub Steiner <jimmac src gnome org>]

commit e497c54c7a34fd3350aaea5c37e0c0b020cdc924
Author: Jakub Steiner <jimmac gmail com>
Date:   Fri Jul 27 15:04:58 2018 +0200

    icons: elaborate on shadows
    
    - alpha channel trickstery
    - mention nightlies

 hig/C/figures/icons/dropshadow.png | Bin 155332 -> 121299 bytes
 hig/C/icon-design.page             |   5 +++--
 2 files changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/hig/C/figures/icons/dropshadow.png b/hig/C/figures/icons/dropshadow.png
index 538a807c..35dd442a 100644
Binary files a/hig/C/figures/icons/dropshadow.png and b/hig/C/figures/icons/dropshadow.png differ
diff --git a/hig/C/icon-design.page b/hig/C/icon-design.page
index 9dc1f246..9a3b31bd 100644
--- a/hig/C/icon-design.page
+++ b/hig/C/icon-design.page
@@ -49,10 +49,11 @@
 <section id="shadows">
 <title>Shadows</title>
 
-<p>You are free to cast shadows internatlly. The light source is coming straight from the top. You
-should avoid casting shadows outside the main silhouette of the icon as icon shadows are generated 
procedurally based on the alpha channel of the icon depending on the context. When app icons are presented on 
a white background, for example, a strong drop shadow is rendered to help define the contours.</p>
+<p>You are free to cast shadows internally. The light source is coming straight from the top. You
+should avoid casting shadows outside the main silhouette of the icon tough, as icon shadows are generated 
procedurally based on the alpha channel of the icon depending on the context. When app icons are presented on 
a white background, for example, a strong drop shadow is rendered to help define the contours.</p>
 <media type="image" mime="image/png" src="figures/icons/dropshadow.png"/>
 
+<p>Having shadows generated automatically depending o context also allows us to prodecurally generate 
versions of the app icon based on the alpha channel contour, such as for application nightly builds.</p>
 </section>
 
 <section id="palette">