Docs: Fix monospace formatting in user guide
Docs: Fix monospace formatting in user guide

Change-Id: I28b2790ff2f87b9fe3cf1020e59e1e0a00be6f97
Signed-off-by: Jeenu Viswambharan <5b289de972918ffd274229d00560f010009baf9e@arm.com>

lsigithub/arm-trusted-firmware_public,sbranden/arm-trusted-firmware,achingupta/arm-trusted-firmware,sbranden/arm-trusted-firmware,lsigithub/arm-trusted-firmware_public,achingupta/arm-trusted-firmware