Add Tidy requirement to the README

diff --git a/README b/README
index 3dd365e1f8218039fae8652ebcb855eda2df8789..75621998111fa1c3f38fe8e30c03d0cdffdc02f2 100644 (file)
--- a/README
+++ b/README
@@ -146,6 +146,7 @@ Your PHP installation must include the following PHP extensions:
 - GD. For scaling down avatar images.
 - mbstring. For handling Unicode (UTF-8) encoded strings.
 - gettext. For multiple languages. Default on many PHP installs.
+- tidy. Used to clean up HTML/URLs for the URL shortener to consume.
 
 For some functionality, you will also need the following extensions: