docs: apply style fixes to live migration docs

I've added newlines between paragraphs and code blocks for easier
reading. I've also changed the code blocks to use the correct
highlighting.

Signed-off-by: Julian Stecklina <julian.stecklina@cyberus-technology.de>

docs/live_migration.md

@@ -9,8 +9,10 @@ support in Cloud Hypervisor:
    are running on the same machine.
 
 ## Local Migration (Suitable for Live Upgrade of VMM)
+
 Launch the source VM (on the host machine):
-```bash
+
+```console
 $ target/release/cloud-hypervisor
     --kernel ~/workloads/vmlinux \
     --disk path=~/workloads/focal.raw \
@@ -20,17 +22,20 @@ $ target/release/cloud-hypervisor
 ```
 
 Launch the destination VM from the same directory (on the host machine):
-```bash
+
+```console
 $ target/release/cloud-hypervisor --api-socket=/tmp/api2
 ```
 
 Get ready for receiving migration for the destination VM (on the host machine):
-```bash
+
+```console
 $ target/release/ch-remote --api-socket=/tmp/api2 receive-migration unix:/tmp/sock
 ```
 
 Start to send migration for the source VM (on the host machine):
-```bash
+
+```console
 $ target/release/ch-remote --api-socket=/tmp/api1 send-migration --local unix:/tmp/sock
 ```
 
@@ -42,9 +47,11 @@ the source VM is terminated gracefully.
 
 Launch VM 1 (on the host machine) with an extra virtio-blk device for
 exposing a guest image for the nested source VM:
+
 > Note: the example below also attached an additional virtio-blk device
 > with a dummy image for testing purpose (which is optional).
-```bash
+
+```console
 $ head -c 1M < /dev/urandom > tmp.img # create a dummy image for testing
 $ sudo /target/release/cloud-hypervisor \
         --serial tty --console off \
@@ -57,7 +64,8 @@ $ sudo /target/release/cloud-hypervisor \
 
 Launch VM 2 (on the host machine) with an extra virtio-blk device for
 exposing the same guest image for the nested destination VM:
-```bash
+
+```console
 $ sudo /target/release/cloud-hypervisor \
         --serial tty --console off \
         --cpus boot=1 --memory size=512M \
@@ -68,7 +76,8 @@ $ sudo /target/release/cloud-hypervisor \
 ```
 
 Launch the nested source VM (inside the guest OS of the VM 1) :
-```bash
+
+```console
 vm-1:~$ sudo ./cloud-hypervisor \
         --serial tty --console off \
         --memory size=128M \
@@ -82,10 +91,12 @@ vm-1:~$ sudo ip addr add 192.168.101.2/24 dev ens4
 vm-1:~$ sudo ip link set up dev ens4
 vm-1:~$ sudo ip r add default via 192.168.101.1
 ```
+
 Optional: Run the guest workload below (on the guest OS of the nested source VM),
 which performs intensive virtio-blk operations. Now the console of the nested
 source VM should repeatedly print `"equal"`, and our goal is migrating
 this VM and the running workload without interruption.
+
 ```bash
 #/bin/bash
 
@@ -107,7 +118,8 @@ echo "tmp = $tmp"
 ```
 
 Launch the nested destination VM (inside the guest OS of the VM 2):
-```bash
+
+```console
 vm-2:~$ sudo ./cloud-hypervisor --api-socket=/tmp/api2
 vm-2:~$ # setup the guest network with the following commands if needed
 vm-2:~$ sudo ip addr add 192.168.102.2/24 dev ens4
@@ -115,20 +127,23 @@ vm-2:~$ sudo ip link set up dev ens4
 vm-2:~$ sudo ip r add default via 192.168.102.1
 vm-2:~$ ping 192.168.101.2 # This should succeed
 ```
+
 > Note: If the above ping failed, please check the iptables rule on the
 > host machine, e.g. whether the policy for the `FORWARD` chain is set
 > to `DROP` (which is the default setting configured by Docker).
 
 Get ready for receiving migration for the nested destination VM (inside
 the guest OS of the VM 2):
-```bash
+
+```console
 vm-2:~$ sudo ./ch-remote --api-socket=/tmp/api2 receive-migration unix:/tmp/sock2
 vm-2:~$ sudo socat TCP-LISTEN:6000,reuseaddr UNIX-CLIENT:/tmp/sock2
 ```
 
 Start to send migration for the nested source VM (inside the guest OS of
 the VM 1):
-```bash
+
+```console
 vm-1:~$ sudo socat UNIX-LISTEN:/tmp/sock1,reuseaddr TCP:192.168.102.2:6000
 vm-1:~$ sudo ./ch-remote --api-socket=/tmp/api1 send-migration unix:/tmp/sock1
 ```