How to set up Linux Mint to boot from software RAID, root on native BTRFS RAID0

Linux Mint does not natively support a RAID setup, so I have decided to record the procedure. Keep in mind that I had previously used the same virtual machine to record another BTRFS video. Also, keep in mind that the GRUB boot loader CAN NOT boot from a BTRFS native multidevice file system. That means that in order to use a bootable RAID system, you need to use mdadm and RAID1 for /boot!