Document installation in Spanish

Signed-off-by: Rafael Cordano <rafael.cordano@gmail.com>
Signed-off-by: Rodrigo Médica <rodrigomedica@hotmail.com>
Signed-off-by: Emmanuel Minetti <emmanuelminetti@gmail.com>
Signed-off-by: Franco Profeti <francokuroneko@gmail.com>

Acked-by: Daniel Francis <francis@sugarlabs.org>