Ajout procédures partie 1 et modifications légères

procedures/1-virtual-machine/connect-serial-vm.md

procedures/1-virtual-machine/connect-virt-server.md

procedures/1-virtual-machine/create-virtual-machine.md

procedures/1-virtual-machine/setup-virtual-network.md

procedures/1-virtual-machine/ssh-alias.md

procedures/1-virtual-machine/ssh-keygen.md

procedures/2-configuration-services/change-hostname.md

procedures/2-configuration-services/postgresql.md

procedures/2-configuration-services/sudo.md

resources/host-univ-lille.png

resources/ip-addr.png

resources/ip-route.png

resources/ping-matrix.png

resources/serial-console.png