Convert Raw disk Image file into Virtual Box `.vdi`

Working with DietPi, we found going back and forth between the Raspberry Pi and PC very time consuming. Fortunately DietPi provides a PC distribution with x86_x64 configuration. Though they had both VM Ware and Virtual Box files but they did not work for us. So we decided to download the Native PC for BIOS/CSM (BETA) option.

We later found out this is just a .img file, we could not directly use it with Virtual Box