UPDATES: updating markdowns to subtitles

doc/deployment_guide/deployment_guide.md

@@ -20,7 +20,7 @@ Virtualization platforms tested are:
 ### 1.1.1. Physical Server
 This page describes how to configure a physical server for running ETSI TeraFlowSDN(TFS) controller.
 
-#### Server Specifications
+<u>Server Specifications</u>
 
 **Minimum Server Specifications for development and basic deployment**
 
@@ -50,11 +50,11 @@ For development purposes, it is recommended to run the VSCode IDE (or the IDE of
 Given that TeraFlowSDN follows a micro-services architecture, for the deployment, it might be better to use many clusterized servers with many slower cores than a single server with few highly performant cores.
 
 
-#### Clusterized Deployment
+<u>Clusterized Deployment</u>
 You might consider creating a cluster of machines each featuring, at least, the minimum server specifications. That solution brings you scalability in the future.
 
 
-#### Networking
+<u>Networking</u>
 No explicit indications are given in terms of networking besides that servers need access to the Internet for downloading dependencies, binaries, and packages while building and deploying the TeraFlowSDN components.
 
 Besides that, the network requirements are essentially the same than that required for running a classical Kubernetes environment. To facilitate the deployment, we extensively use [MicroK8s](https://microk8s.io/), thus the network requirements are, essentially, the same demanded by MicroK8s, especially, if you consider creating a Kubernetes cluster.
@@ -69,7 +69,7 @@ The minimum required ports to be accessible are:
 Other ports might be required if you consider to deploy addons such as Kubernetes observability, etc. The details on these ports are left appart given they might vary depending on the Kubernetes environment you use.
 
 
-#### Operating System
+<u>Operating System</u>
 
 The recommended Operating System for deploying TeraFlowSDN is [Ubuntu Server 22.04 LTS](https://releases.ubuntu.com/jammy/) or [Ubuntu Server 20.04 LTS](https://releases.ubuntu.com/focal/). Other version might work, but we have not tested them. We strongly recommend using Long Term Support (LTS) versions as they provide better stability.
 
@@ -101,7 +101,7 @@ Below we provide some installation guidelines:
   - This operation might take some minutes depending on how old is the Optical Drive ISO image you use and your Internet connection speed.
 - Restart the VM when the installation is completed.
 
-#### Upgrade the Ubuntu distribution
+<u>Upgrade the Ubuntu distribution</u>
 ```bash
 sudo apt-get update -y
 sudo apt-get dist-upgrade -y
@@ -113,7 +113,7 @@ sudo apt-get dist-upgrade -y
 
 This page describes how to configure a VM for running ETSI TeraFlowSDN(TFS) controller using [Oracle VirtualBox](https://www.virtualbox.org/). It has been tested with VirtualBox up to version 6.1.40 r154048.
 
-#### Create a NAT Network in VirtualBox
+<u>Create a NAT Network in VirtualBox</u>
 In "Oracle VM VirtualBox Manager", Menu "File > Preferences... > Network", create a NAT 
 network with the following specifications:
 
@@ -131,7 +131,7 @@ forwarding rules:
 
 __Note__: IP address 10.0.2.10 is the one that will be assigned to the VM.
 
-#### Create VM in VirtualBox:
+<u>Create VM in VirtualBox:</u>
 
 - Name: TFS-VM
 - Type/Version: Linux / Ubuntu (64-bit)
@@ -148,7 +148,7 @@ __Note__: IP address 10.0.2.10 is the one that will be assigned to the VM.
 
 __Note__: (*) settings to be editing after the VM is created.
 
-#### Install Ubuntu 22.04 LTS Operating System
+<u>Install Ubuntu 22.04 LTS Operating System</u>
 In "Oracle VM VirtualBox Manager", start the VM in normal mode, and follow the 
 installation procedure.
 Below we provide some installation guidelines:
@@ -179,7 +179,7 @@ Below we provide some installation guidelines:
   - This operation might take some minutes depending on how old is the Optical Drive ISO image you use and your Internet connection speed.
 - Restart the VM when the installation is completed.
 
-##### Upgrade the Ubuntu distribution
+**Upgrade the Ubuntu distribution**
 ```bash
 sudo apt-get update -y
 sudo apt-get dist-upgrade -y
@@ -188,7 +188,7 @@ sudo apt-get dist-upgrade -y
 - Restart the VM when the installation is completed.
 
 
-##### Install VirtualBox Guest Additions
+**Install VirtualBox Guest Additions**
 On VirtualBox Manager, open the VM main screen. If you are running the VM in headless 
 mode, right click over the VM in the VirtualBox Manager window and click "Show".
 If a dialog informing about how to leave the interface of the VM is shown, confirm 
@@ -211,7 +211,7 @@ sudo reboot
 
 This page describes how to configure a VM for running ETSI TeraFlowSDN(TFS) controller using [VMWare Fusion](https://www.vmware.com/products/fusion.html). It has been tested with VMWare Fusion version 12 and 13.
 
-#### Create VM in VMWare Fusion:
+<u>Create VM in VMWare Fusion:</u>
 
 In "VMWare Fusion" manager, create a new network from the "Settings/Network" menu.
 
@@ -237,7 +237,7 @@ On the next screen press "Customize Settings", save the VM and in "Settings" cha
 
 Run the VM to start the installation.
 
-#### Install Ubuntu 22.04.1 LTS Operating System
+<u>Install Ubuntu 22.04.1 LTS Operating System</u>
 
 The installation will be automatic, without any configuration required.
 
@@ -258,7 +258,7 @@ The installation will be automatic, without any configuration required.
 
 - Restart the VM when the installation is completed.
 
-#### Upgrade the Ubuntu distribution
+<u>Upgrade the Ubuntu distribution</u>
 ```bash
 sudo apt-get update -y
 sudo apt-get dist-upgrade -y