Improve main navigational menu structure

[kernc]

Proposing improved main navigational menu structure on the main website:

• Pridruži se!
• Koledar
• Delovanje
  • POT
  • SU
  • * Meet-up
  • Pravna pisarna
  • CoderDojo
  • ... (one [description + calendar filter + comments ...] page per each regular program/activity)
• Video
• O nas
  • Zgodovina
  • Skupnost — alumni page
  • Galerija
  • Za medije (press)
• Podprite nas
  • item wishlist

And its English counterpart on /en/.