No its nothing to do with missing imans, its when the Prophet Muhammad p.b.u.h was ascended to heaven with Gabriel and met some of the other prophets such as Abraham, Moses, Enoch and Jesus and also the 5 times prayer was revealed. It is a historically important event but it does not mean that we have to do any extra worship on that night as there is no evidence for doing any extra worship in the Quran and sunnah. Hope this helps!