Add chapter on Cell Broadcast Support in Osmocom (to BSC+NITB manual)

Change-Id: I2c621def499dc0564d31eb9440e22e79948a5466
diff --git a/doc/manuals/osmobsc-usermanual.adoc b/doc/manuals/osmobsc-usermanual.adoc
index 25bd35b..9323373 100644
--- a/doc/manuals/osmobsc-usermanual.adoc
+++ b/doc/manuals/osmobsc-usermanual.adoc
@@ -27,6 +27,8 @@
 
 include::../common/chapters/control_if.adoc[]
 
+include::../common/chapters/cell-broadcast.adoc[]
+
 include::../common/chapters/port_numbers.adoc[]
 
 include::../common/chapters/bibliography.adoc[]