Added documentation

README.md

 # Scaleway Instances Template - Quickstart
 
-## How does it work ?
+# How does it work ?
 
 The template will provision several resources (including your instances) to the Scaleway cloud provider using Terraform and Gitlab CI.
 After provisioning, configuration of the instances and deployment of the services (Atrium and TTYD) will be done using Cloud-init and bash scripts.
 
 > All your information must be stored in Gitlab and passed as variable to Terraform.
 
-### How the deployment is managed ?
+## How the deployment is managed ?
 
 The whole project is managed by Gitlab using the Gitlab CI. 
 Launching the pipeline will start the deployment of your infrastructure in 3 steps.  
 
-**Plan :**
+**Plan :**  
 Terraform will perform a "fake deployment" and initialize everything he needs before deploying.  
-After performing, you will be able to see the plan of the future creation/modification/destruction in the log of the pipeline.
-If the modification could lead to break changes and errors, you must not launch the next step of the pipeline.
-**Creation :**
-Terraform will be applying the exact changes you reviewed in the Plan step.
-**Destruction :**
-Terraform will destroy the resources he managed to create (or manually imported one).
+After performing, you will be able to see the plan of the future creation/modification/destruction in the log of the pipeline.  
+If the modification could lead to break changes and errors, you must not launch the next step of the pipeline.  
+**Creation :**  
+Terraform will be applying the exact changes you reviewed in the Plan step.  
+**Destruction :**  
+Terraform will destroy the resources he managed to create (or manually imported one).  
 
-## How can I use it ?
+##How can I use it ?
 
-### Step 0 : Prerequisite
+## Step 0 : Prerequisite
 
 **On The Forge (Gitlab)**, you must have or ask for the right to fork the repository.  
 
@@ -33,11 +33,11 @@ and create one for your project. Please make sure to add a description starting
 **The Certificate Authority (CA)** Let's Encrypt needs an email. He will use it to send a notification before the certificate expires to proceed with
 the renewal.  
 
-### Step 1 : Getting your own repository
+## Step 1 : Getting your own repository
 
 Fork the project from [this repository](https://forge.grandlyon.com/systemes-dinformation/alpha/pocs/scaleway-instances-template)
 
-### Step 2 : Setting up the variables with credentials and others information
+## Step 2 : Setting up the variables with credentials and others information
 
 Go to the `Settings` menu, `CI/CD` and look for the `Variables` submenu.  
 Once it's done, you will need to create the variable bellow :  
@@ -50,7 +50,7 @@ Once it's done, you will need to create the variable bellow :
 - **TF_VAR_SCW_SECRET_KEY** : Scaleway Secret Key.  
 - **TF_VAR_USER_PASSWORD** : User password for accessing services and instances.  
 
-### Step 3 : Every is set up, deployment is coming !
+## Step 3 : Every is set up, deployment is coming !
 
 Go the `CI/CD` menu and `Pipelines`.  
 From now, you will need to click on `Run pipeline` with your selected branch.  
@@ -63,7 +63,7 @@ on production infrastructure.
 Once plan is done and ok, click the `Apply button` to deploy the infrastructure. Please be sure to click the `Destroy
 button` to destroy the infrastructure when you don't need it anymore.
 
-### Step 4 : Accessing your services
+## Step 4 : Accessing your services
 
 After deployment, each resource can be accessed though HTTPS, URL depends of the variable you defined before :
 - **TTYD :** https://terminal-<INSTANCE_COUNT>.<ENVIRONMENT>-<INSTANCE_COUNT>.<PROJECT_DOMAIN/