plugin/autopath docs: remove last use of middleware
This has somehow survived; the docs still used Middleware instead of
Plugins.
@@ -20,7 +20,7 @@ through the search path.
It is assume the search path ordering is identical between server and client.
-Middleware implementing autopath, must have a function called `AutoPath` of type
+Plugins implementing autopath, must have a function called `AutoPath` of type
autopath.Func. Note the searchpath must be ending with the empty string.
I.e:
