fix various typos across all manuals
diff --git a/doc/manuals/chapters/overview.adoc b/doc/manuals/chapters/overview.adoc
index e13a7b8..0031474 100644
--- a/doc/manuals/chapters/overview.adoc
+++ b/doc/manuals/chapters/overview.adoc
@@ -6,7 +6,7 @@
 Unit) element inside the GPRS network.
 
 The OsmoPCU is co-located within the BTS and connects to OsmoBTS via its
-PCU socket inteface.
+PCU socket interface.
 
 On the other side, OsmoPCU is connected via the Gb interface to the
 SGSN.