create index pages for all folders

account/index.markdown

attic/index.markdown

audience/administrator_of_a_lab_pc.markdown

audience/index.markdown

audience/it_coordinator_at_a_d-phys_research_group.markdown

audience/new_laptop_owner.markdown

audience/new_member_of_d-phys.markdown

backups/backup_of_workstations.markdown

backups/index.markdown

calendar/index.markdown

documentation/how_to_use_ssh.markdown

documentation/index.markdown

index.markdown

index.markdown

linux/index.markdown

mail/index.markdown

media/index.markdown

network/index.markdown

network/wie_bekomme_ich_netzzugang.markdown

osx/index.markdown