DOC: update "3.2 Lancer une mise à jour" section

remove the update black pop-up screenshot

(from redmine: issue id 1419, created on 2015/07/09 by Matthieu Decorde)

added type::doc type::task + 1 deleted label

changed milestone to %TXM 0.8.4

removed type::task label

added status::rejected label

The popup has been removed.

closed