Revise the manual installation document for Arm64 platform
Revise the manual installation document for Arm64 platform

Revise the installation document to reflect the exact meaning and
grammar requirement for Arm64 platform.

Signed-off-by: trevortao <215a608758adc496e5994cb6a15aef6c78b0b040@arm.com>

milanlenco/vpp-1,milanlenco/vpp-1,milanlenco/vpp-1,rastislavszabo/vpp,rastislavszabo/vpp,rastislavszabo/vpp,brecode/vpp,brecode/vpp,brecode/vpp,milanlenco/vpp-1,rastislavszabo/vpp,brecode/vpp,rastislavszabo/vpp,rastislavszabo/vpp,brecode/vpp,rastislavszabo/vpp,milanlenco/vpp-1