Short project planning

Nov 27, 2021

New in version 2.2
- recoding generation of PDF files to use the Android PDF library and the mobile default character set,
- minimum SDK level put to 21 (Android 5) in order to use Android PDF library and Google services new versions, and adaptations to use App Bundle format,
- in Gantt charts, problems fixing and adding possibility of vertical zooming,
- problems fixing.