10.0.15: Update README.md

[version 10.0.15] (https://github.com/PhDLeToanThang/itil-helpdesk/releases/latest)

[THE LATEST STABLE GLPI VERSION]
ITIL VERSION 10.0.15 : 03/05/2024 – Archive TGZ – 56.9MB

version 10.0.12

[version 10.0.12] (https://github.com/PhDLeToanThang/itil-helpdesk/releases/latest)

[THE LATEST STABLE GLPI VERSION]
ITIL VERSION 10.0.12 : 03/03/2024 – Archive TGZ – 56.7MB

version 10.0.6

[THE LATEST STABLE GLPI VERSION]
ITIL VERSION 10.0.6 : 05/04/2023 – Archive TGZ – 33.4Mo