initial checkin of manuals to public repo

The manuals existed in different form for several years in an internal
sysmocom repository.  However, since they had just recently been
converted from docboox-xml to asciidoc and all files have been
re-shuffled for enabling the public release, there's not much point in
keeping the history with git-filter-branch.
diff --git a/doc/manuals/vty/osmo-pcu_vty_additions.xml b/doc/manuals/vty/osmo-pcu_vty_additions.xml
new file mode 100644
index 0000000..55d75e4
--- /dev/null
+++ b/doc/manuals/vty/osmo-pcu_vty_additions.xml
@@ -0,0 +1,9 @@
+<vtydoc xmlns='urn:osmocom:xml:libosmocore:vty:doc:1.0'>
+    <node id='14'>
+    <child_of id='4' />
+    <name>PCU Configuration Node</name>
+    <description>The main PCU configuration including the timeslot
+    assignment algorithm and other parameters.</description>
+    </node>
+</vtydoc>
+