* bump version to 4.8.0

* update benchmark results on i7 & rpi

* correct python command on i7

* update results on jetson nano

* update results on atlas 200 cpu

* update results on vim3 cpu, sunrise x3 cpu

* update results on vim3 npu

* update results on edge2

* update results on rv1126 and vision2

* update results on axp

* update table