[dconf] docs: mention nfs in the overview docs

[Matthias Clasen <matthiasc src gnome org>]

commit ff7cca187362093a056dd84e085100c0bdab6ee6
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Jul 16 18:34:08 2013 -0400

    docs: mention nfs in the overview docs
    
    The keyfile backend was not mentioned at all in the shipped
    docs so far.

 docs/dconf-overview.xml |   15 +++++++++++++++
 1 files changed, 15 insertions(+), 0 deletions(-)
---
diff --git a/docs/dconf-overview.xml b/docs/dconf-overview.xml
index 3700bb4..b1cfadf 100644
--- a/docs/dconf-overview.xml
+++ b/docs/dconf-overview.xml
@@ -64,6 +64,21 @@
   </refsect1>
 
   <refsect1>
+    <title>NFS</title>
+
+    <para>
+      The binary database format that dconf uses by default is not suitable for use on NFS, where mmap does 
not
+      work well. To handle this common use case, dconf can be configured to use a plain text keyfile instead 
of
+      a binary database. The keyfile is put in the <filename><envar>$XDG_CONFIG_HOME</envar>/dconf</filename>
+      directory.
+    </para>
+    <para>
+      To enable keyfile storage, add a line containing <literal>service-db:keyfile/user</literal> to the file
+      <filename>/etc/dconf/profile/user</filename>.
+    </para>
+  </refsect1>
+
+  <refsect1>
     <title>Portability</title>
 
     <para>