Add jupiter USB key

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/jupiter/README.md

@@ -1,6 +1,15 @@
 # jupiter
 
-## Post-Install Checklist
+## Creating a USB key
+
+```sh
+sudo fdisk /dev/sdx
+# o, n, p, <enter>, <enter>, <enter>, t, b, w
+sudo mkfs.vfat -F 32 /dev/sdx1
+mkdir -p /mnt/luks
+sudo mount /dev/sdx1 /mnt/luks
+echo -n "key" | sudo tee /mnt/luks/keyfile
+```
 
 ## RAID Management