Simplified instructions and added a note on the performance penalty.

README.txt

@@ -9,7 +9,7 @@ use to provide a replacement in your own package. Simply register a
 template overrides directory and give your new template the canonical
 filename.
 
-Overrides may be registered for a specific request-layer.
+Overrides may be registered for a specific layer or any layer.
 
 
 Canonical filename
@@ -28,12 +28,8 @@ Example:
 Registering a on overrides directory
 ------------------------------------
 
-In python:
-
-  >>> from z3c.jbot.utility import getManager
-  >>> getManager().registerDirectory(directory)
-
-Using ZCML:
+A Zope component configuration directive is available to configure
+overrides.
 
   <include package="z3c.jbot" file="meta.zcml" />
 
@@ -42,6 +38,14 @@ Using ZCML:
       layer="<layer>" />
 
 
+Performance considerations
+--------------------------
+
+The use of jbot adds to the general page load time. On a site with
+many templates this may be as much as 25 ms per request (a 9% increase
+on my machine).
+
+
 Author
 ------