ref-manual: Added "meta/lib/" directory and moved it.

Placed the "meta/lib/" and "meta/files/" descriptions
beneath "meta/conf/*" to match the actual repo.

(From yocto-docs rev: 74b9cb2b42db7f6acd5a19a1856ede98ff29e775)

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

documentation/ref-manual/ref-structure.xml

@@ -608,6 +608,26 @@
         </para>
     </section>
 
+    <section id='structure-meta-files'>
+        <title><filename>meta/files/</filename></title>
+
+        <para>
+            This directory contains common license files and several text files
+            used by the build system.
+            The text files contain minimal device information and
+            lists of files and directories with knows permissions.
+        </para>
+    </section>
+
+    <section id='structure-meta-lib'>
+        <title><filename>meta/lib/</filename></title>
+
+        <para>
+            This directory contains OpenEmbedded Python library code
+            used during the build process.
+        </para>
+    </section>
+
     <section id='structure-meta-recipes-bsp'>
         <title><filename>meta/recipes-bsp/</filename></title>