[release-notes/gnome-3-20] Add a screenshot of GTK+ Inspector

[Andreas Nilsson <andreasn src gnome org>]

commit da43590912b11c6f5fc98e3dbd52ec7b2c6a3769
Author: Andreas Nilsson <anilsson redhat com>
Date:   Tue Mar 15 18:47:50 2016 +0100

    Add a screenshot of GTK+ Inspector

 help/C/developers.page           |    2 +-
 help/C/figures/gtk-inspector.png |  Bin 0 -> 249281 bytes
 help/Makefile.am                 |    3 ++-
 3 files changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/help/C/developers.page b/help/C/developers.page
index a50e13a..8e2e5c4 100644
--- a/help/C/developers.page
+++ b/help/C/developers.page
@@ -190,7 +190,7 @@
 
   <section id="gtk-inspector">
     <title>GTK+ Inspector</title>
-    <media type="image" src="figures/placeholder.png"/>
+    <media type="image" src="figures/gtk-inspector.png"/>
     <p>GTK+’s live inspector has had a number of updates for 3.20:</p>
     <list>
       <item><p>The user interface has been polished: the sidebar has been
diff --git a/help/C/figures/gtk-inspector.png b/help/C/figures/gtk-inspector.png
new file mode 100644
index 0000000..5382308
Binary files /dev/null and b/help/C/figures/gtk-inspector.png differ
diff --git a/help/Makefile.am b/help/Makefile.am
index b6835bf..aadf390 100644
--- a/help/Makefile.am
+++ b/help/Makefile.am
@@ -23,6 +23,7 @@ HELP_MEDIA = \
  figures/location-services-privacy.png \
  figures/media-controls.png \
  figures/xdg-app.png \
- figures/cantarell.png
+ figures/cantarell.png \
+ figures/gtk-inspector.png
 
 HELP_LINGUAS = cs es gl