Doc updated

doc/todo.txt

@@ -31,6 +31,12 @@ Table of Contents                                          *TodoTxt-Contents* ~
 ===============================================================================
 1. Release notes                                       *TodoTxt-ReleaseNotes* ~
 
+v0.7.4 includes the overduedate support from Guilherme Victal (see pull
+request #45 on freitass version (https://github.com/freitass/todo.txt-vim/pull/45)),
+it highlight dates in overdue tasks as an Error. It depends on a
+Python library, however, and as such will only be able to work if your version
+of Vim was compiled with the `+python` option (as most common versions do).
+
 Since v0.7.3, `TodoComplete` is replaced by `todo#Complete`, you might need to
 update your vimrc (see |TodoTxt-Completion|).