Typo fix.

doc/apt-get.8.xml

@@ -506,7 +506,7 @@
      </varlistentry>
      
      <varlistentry><term><filename>/etc/apt/apt.conf.d/</filename></term>
-     <listitem><para>APT configuration file fragments
+     <listitem><para>APT configuration file fragments.
      Configuration Item: <literal>Dir::Etc::Parts</literal>.</para></listitem>
      </varlistentry>