[shotwell] Add shortcuts for next/previous photo

[Jens Georg <jensgeorg src gnome org>]

commit a441e12512a2e73b446a7c06c324e7467f517384
Author: Jens Georg <mail jensge org>
Date:   Thu Mar 26 12:41:23 2020 +0100

    Add shortcuts for next/previous photo
    
    Fixes #226

 data/ui/direct.ui | 2 ++
 data/ui/photo.ui  | 2 ++
 2 files changed, 4 insertions(+)
---
diff --git a/data/ui/direct.ui b/data/ui/direct.ui
index f079ff80..8407ec58 100644
--- a/data/ui/direct.ui
+++ b/data/ui/direct.ui
@@ -100,10 +100,12 @@
         <item>
           <attribute name="label" translatable="yes">_Previous Photo</attribute>
           <attribute name="action">win.PrevPhoto</attribute>
+          <attribute name="accel">Left</attribute>
         </item>
         <item>
           <attribute name="label" translatable="yes">_Next Photo</attribute>
           <attribute name="action">win.NextPhoto</attribute>
+          <attribute name="accel">Right</attribute>
         </item>
       </section>
       <section>
diff --git a/data/ui/photo.ui b/data/ui/photo.ui
index dc69a7c2..5e735510 100644
--- a/data/ui/photo.ui
+++ b/data/ui/photo.ui
@@ -194,9 +194,11 @@
         <item>
           <attribute name="label" translatable="yes">_Previous Photo</attribute>
           <attribute name="action">win.PrevPhoto</attribute>
+          <attribute name="accel">Left</attribute>
         </item>
         <item>
           <attribute name="label" translatable="yes">_Next Photo</attribute>
+          <attribute name="accel">Right</attribute>
           <attribute name="action">win.NextPhoto</attribute>
         </item>
       </section>