Ubiquiti EdgeRouter Lite instructions gloss over file system creation when using new USB flash drive

I started from a new (previously unused) USB flash drive and followed along the instructions until sudo mount /dev/sdb1 kernel, which gave me the following error:

mount: /home/xxx/Downloads/openwrt_edgerouter_lite/kernel: wrong fs type, bad option, bad superblock on /dev/sdb1, missing codepage or helper program, or other error.

I fixed it by creating a file system in the first partition:

sudo mkfs.fat -F 32 /dev/sdb1

Should the instructions perhaps mention this somewhere?