Revert "docs: Address issue with ISOHYBRIDs and some BIOS systems. Closes #470"

This reverts commit 9f937d9.

Author: Mintsuki

USAGE.md

@@ -74,15 +74,6 @@ xorriso -as mkisofs -R -r -J -b <relative path of limine-bios-cd.bin> \
 
 *Note: `xorriso` is required.*
 
-For better compatibility with BIOS/CSM systems that refuse to boot from disks that
-have a GPT partition table, one can convert the GPT table generated by `xorriso`
-into an MBR by using `sgdisk` with the following command:
-```
-sgdisk image.iso -m 1:2:3:4
-```
-
-*Note: `sgdisk` is required, usually from a `gdisk` or `gptfdisk` package*
-
 And do not forget to also run `limine bios-install` on the generated image:
 ```
 limine bios-install image.iso