ref-manual: Added more detail to BB_GENERATE_MIRROR_TARBALLS variable.

Fixes [YOCTO #5684]

Added a clause to note that the tarballs saved to the DL_DIR area
include the Git metadata.

Reported-by: Laszlo Papp <lpapp@kde.org>
(From yocto-docs rev: 76cbb8a149b9fda6879f9dfc6a17dab992325e94)

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/ref-manual/ref-variables.xml

@@ -525,9 +525,13 @@
         <glossentry id='var-BB_GENERATE_MIRROR_TARBALLS'><glossterm>BB_GENERATE_MIRROR_TARBALLS</glossterm>
             <glossdef>
                 <para>
-                    Causes tarballs of the Git repositories to be placed in the
+                    Causes tarballs of the Git repositories, including the
+                    Git metadata, to be placed in the
                     <link linkend='var-DL_DIR'><filename>DL_DIR</filename></link>
                     directory.
+                </para>
+
+                <para>
                     For performance reasons, creating and placing tarballs of
                     the Git repositories is not the default action by the
                     OpenEmbedded build system.