manual update, multiboot image locations comment

doc/MANUAL.md

@@ -238,7 +238,7 @@ bootloader image is at byte address 0 of SPI config FLASH, "golden"
 bootloader image is at 0x140000 address on 45F chip but its location
 varies on various sizes of FPGA 12/25/45/85F. At the last 256 bytes of
 FLASH are some special FPGA lattice boot state machine commands
-(like some primitive CPU assemlby) than setups and controls multiboot
+(like some primitive CPU assemlby) that setups and controls multiboot
 function. Try not to overwrite any of boot realted areas with something
 else otherwise US1 or JTAG recovery will be required.