Complete change of slide 1.1

Changed slides order to facilitate transitions
Added structure slides to help trainees follow
Changed slides content to vulgarize
Added exercises slides
Added exercise material folder and doc, for trainees to complete the
exercises given
Slide 1.1 - Added document deletion slides

Slide 1.1 - Added document deletion slides
Slide 1.1 - corrections

Corrected typos
Modified a few slides
Slide 4.3 Removed a duplicate slide

Slide 4.3 Removed a duplicate slide