ref-manual: Added descriptions for 5 new variables and 2 tasks.

Fixes [YOCTO #8019]

Added new descriptions for five kernel variables and two tasks.

(From yocto-docs rev: 834aebb75dce1c905b1e0f142d0d7de6bb44e7d4)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/ref-manual/ref-tasks.xml

@@ -619,6 +619,15 @@
         </para>
     </section>
 
+    <section id='ref-tasks-kernel_metadata'>
+        <title><filename>do_kernel_metadata</filename></title>
+
+        <para>
+            Collects kernel metadata for a
+            <filename>linux-yocto</filename> style kernel.
+        </para>
+    </section>
+
     <section id='ref-tasks-menuconfig'>
         <title><filename>do_menuconfig</filename></title>
 
@@ -638,6 +647,14 @@
         </para>
     </section>
 
+    <section id='ref-tasks-shared_workdir'>
+        <title><filename>do_shared_workdir</filename></title>
+
+        <para>
+            Creates the shared working directory for the kernel.
+        </para>
+    </section>
+
     <section id='ref-tasks-sizecheck'>
         <title><filename>do_sizecheck</filename></title>