Update INSTALL file

diff --git a/INSTALL b/INSTALL
index 02a4a07..7285007 100644
--- a/INSTALL
+++ b/INSTALL
@@ -1,3 +1,7 @@
+**** NOTE ****
+The instructions below may be outdated.
+Please see https://wiki.trinitydesktop.org/How_to_Build_TDE_Core_Modules for the latest build information.
+
 Basic Installation
 ==================