doc: More cross-references; Expand overview slightly

Change-Id: Ic290627ec2512a2b59cb9d81704b9cec4d14ccf4
diff --git a/doc/manuals/chapters/remsim-bankd.adoc b/doc/manuals/chapters/remsim-bankd.adoc
index a3a1921..e76afd5 100644
--- a/doc/manuals/chapters/remsim-bankd.adoc
+++ b/doc/manuals/chapters/remsim-bankd.adoc
@@ -1,3 +1,4 @@
+[[remsim-bankd]]
 == osmo-remsim-bankd
 
 The `osmo-remsim-bankd` (SIM Bank Daemon) manages one given SIM bank.