Add VTY reference manual

Fixes: OS#2589
Change-Id: I042734fa9979b598d5471839e408cbf39bba57b5
diff --git a/doc/manuals/regen_doc.sh b/doc/manuals/regen_doc.sh
new file mode 100755
index 0000000..39dd9ee
--- /dev/null
+++ b/doc/manuals/regen_doc.sh
@@ -0,0 +1,17 @@
+#!/bin/sh -x
+
+if [ -z "$DOCKER_PLAYGROUND" ]; then
+	echo "You need to set DOCKER_PLAYGROUND"
+	exit 1
+fi
+
+SCRIPT=$(realpath "$0")
+MANUAL_DIR=$(dirname "$SCRIPT")
+
+COMMIT=${COMMIT:-$(git log -1 --format=format:%H)}
+
+cd "$DOCKER_PLAYGROUND/scripts" || exit 1
+
+OSMO_SGSN_BRANCH=$COMMIT ./regen_doc.sh osmo-hnbgw 4261 \
+	"$MANUAL_DIR/chapters/counters_generated.adoc" \
+	"$MANUAL_DIR/vty/hnbgw_vty_reference.xml"