Cleaned up Annual Report folders structure

["Jeff F. T." <nekohayo gmail com>]

Hi all,

Just to let you know I fixed something that caused a lot of confusion
because of the whole calendar-vs-fiscal year thing: the annual reports'
folder naming in our git repo.

The fix:
https://github.com/gnome-design-team/gnome-marketing/commit/cceb175147

So it went from:

/annual-report
/annual-report-2014
/annual-report-2015

…to:

/annual-report/
              /FY2012
              /FY2013
              /FY2014

I did the renaming "cleanly", so I suspect the change should take zero time to synchronize when you do your 
next pull.


I'm thinking we could do a similar cleanup for the conferences/events-related folders (the various editions 
of GUADEC are all over the place, for example). I'd like you folks to propose the new hierarchical folder 
structure for this, and I'll be happy to effect the changes.