update development deb packages

diff --git a/README b/README
index 24c577b..e19d4c1 100644 (file)
--- a/README
+++ b/README
@@ -32,7 +32,7 @@ sudo apt-get install \
 you may need one of the following packages for development:
 
 sudo apt-get install \
-       make perl-doc libxml2-utils
+       make perl-doc libxml2-utils tidy
 
 and may enable mod_apreq