Add initial osmo-remsim usermanual

Change-Id: I1d9231b24b1481afcbb5758662b7d99bd59e7fdb
diff --git a/doc/Makefile.am b/doc/Makefile.am
new file mode 100644
index 0000000..adfdcf7
--- /dev/null
+++ b/doc/Makefile.am
@@ -0,0 +1,3 @@
+SUBDIRS = \
+	manuals \
+        $(NULL)