Restructure readme content

README.md

@@ -78,7 +78,7 @@ If one process hangs on a long running message method it will not affect the res
 
 ### Logical structure
 
-![overview](steward.svg)
+![overview](doc/steward.svg)
 
 ## Terminology
 

subscriber_method_types.go

@@ -185,7 +185,9 @@ func (m Method) GetMethodsAvailable() MethodsAvailable {
 	return ma
 }
 
-// Reply methods
+// Reply methods. The slice generated here is primarily used within
+// the Stew client for knowing what of the req types are generally
+// used as reply methods.
 func (m Method) GetReplyMethods() []Method {
 	rm := []Method{REQToConsole, REQToFile, REQToFileAppend}
 	return rm