[LGM] presentation requirements

[ale rimoldi]

hi

while we where looking for the best ways to give feedback for the
proposal, we have worked on a text that should help the presenters
propose better talks.

i've now the copied on the lgm site:

http://libregraphicsmeeting.org/lgm/public-documentation/presentation-requirements/

hopefully we can improve on that and use it for the future lgms!

ciao
a.l.e