[atk] docs: change id of the atkobject chapter

[Alejandro Piñeiro Iglesias <apinheiro src gnome org>]

commit 7be6652bec1dfe96c605a321d01e3f4af43de172
Author: Alejandro Piñeiro <apinheiro igalia com>
Date:   Fri Sep 30 12:27:57 2016 +0200

    docs: change id of the atkobject chapter
    
    The reason is avoid collision with AtkObject.html on case-insensitive
    filesystems.
    
    One could argue that having a small html that just list AtkObject,
    but this is done automatically by gtk-doc.
    
    One could argue again, saying that probably the current chapter-split
    main page (at atk-docs.sgml) is not the correct one, but I think
    that for now a small id rename is better that a full main page
    overhaul.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=772236

 docs/atk-docs.sgml |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/docs/atk-docs.sgml b/docs/atk-docs.sgml
index 92236a4..2d9991e 100644
--- a/docs/atk-docs.sgml
+++ b/docs/atk-docs.sgml
@@ -64,7 +64,7 @@
 
   </chapter>
 
-  <chapter id="atkobject">
+  <chapter id="base-object">
     <title>Base accessibility object</title>
     &atk-AtkObject;
   </chapter>