adding titles corresponding to the git repo tutorial

docs/tutorial/preliminary.rst

@@ -6,8 +6,8 @@ Getting started
    We will learn how to:
 
    - create a :term:`structure description file <structure file>`
-   - add a :term:`structure file format version <structure file>`
+   - add a :term:`structure file <structure file>` format version in the structure file
-   - add a :term:`variable` and set its :term:`value`
+   - add a :term:`variable` in the structure file and set its default :term:`value`
 
 .. prerequisites:: Prerequisites
 
@@ -36,13 +36,11 @@ Creating a structure file
 - First, we will create a :term:`structure file <structure file>`, so let's create a :file:`00-proxy.yml` file
   located in the :file:`firefox` subfolder.
 
-.. type-along:: An empty structure file
-
 This is an empty Rougail :term:`structure description file: <structure file>` 
 
 .. extinclude:: https://forge.cloud.silique.fr/stove/rougail-tutorials/raw/tag/v1.1_000/firefox/00-proxy.yml
    :language: yaml
-   :caption: An empty rougail dictionnary file with the version number only
+   :caption: An empty rougail structure file with only the YAML header and the version number
    :name: RougailStructVersion
 
 .. 
@@ -51,16 +49,27 @@ This is an empty Rougail :term:`structure description file: <structure file>`
 
 :tutorial:`Download this file from the rougail-tutorials git repository <src/tag/v1.1_000/firefox/00-proxy.yml>`
 
+This `version` specification is just the rougail YAML's format version specification. 
+By now, we have an empty structure file with the format specification in it. 
+
 Let's add our first variable
 ------------------------------
 
-.. note:: A variable is defined at a minimum by its name.
+.. type-along:: For those who follow the tutorial with the help of the git repository
 
-A :term:`variable` in the :term:`structure description file <structure file>`
+    Now you need to checkout the `v1.1_001` version::
+     
+          git checkout v1.1_001
+
+
+- A variable is defined at a minimum by its name.
+- A :term:`variable` lives in the :term:`structure description file <structure file>`.
+
+Here we define a variable named `proxy_mode`:
 
 .. extinclude:: https://forge.cloud.silique.fr/stove/rougail-tutorials/raw/tag/v1.1_001/firefox/00-proxy.yml
    :language: yaml
-   :caption: A Rougail structure file with only one variable
+   :caption: A Rougail structure file with only one variable in it
    :name: RougailDictionaryFirstVariableName
 
 .. 
@@ -69,14 +78,14 @@ A :term:`variable` in the :term:`structure description file <structure file>`
 
 :tutorial:`Download this file from the rougail-tutorials git repository <src/tag/v1.1_001/firefox/00-proxy.yml>`
 
-Let's run the Rougail CLI utility command:
+Let's run the Rougail CLI utility command in a terminal:
 
 .. code-block:: text
    :class: terminal
    
     rougail -m firefox/
 
-we will actually have an error: 
+Well, we notice that we have an error: 
 
 .. raw:: html
    :url: https://forge.cloud.silique.fr/stove/rougail-tutorials/raw/tag/v1.1_001/config/01/output_ro.html
@@ -87,7 +96,7 @@ we will actually have an error:
     ┣━━ The following variables are mandatory but have no value:
     ┗━━   - proxy_mode
 
-Because this variable is :term:`mandatory` and needs to be set **but** there's no value yet.
+It's because this first defined variable is :term:`mandatory` and needs to have a value set **but** there's no value yet.
 
 We can therefore deduce the fact that:
 
@@ -105,13 +114,25 @@ Rougail waits for the `proxy_mode` configuration option's value to be set.
         A variable is mandatory when a value is required, that is, `None` **is not** a possible value.
         It **must** have a defined value.
 
-.. seealso:: To go further, have a look at the :tiramisu:`mandatory option <glossary.html#term-mandatory-option>` according to the definition of Tiramisu.
+.. seealso:: To go further, have a look at the :tiramisu:`mandatory option <glossary.html#term-mandatory-option>` 
+    according to the :xref:`Tiramisu <tiramisu>` underlyning consistency system. 
+    You will learn that it is actually possible to disable the mandatory property behavior, 
+    but you need to declare it explicitely.
+
+Describe the variable
+-------------------------
         
-Let's add a variable's description, which is not mandatory but which is a good practice:
+Let's add a variable's description, which is not mandatory but which is usually a good practice.
+
+.. type-along:: For those who follow the tutorial with the help of the git repository
+
+    Now you need to checkout the `v1.1_002` version::
+     
+          git checkout v1.1_002
 
 .. extinclude:: https://forge.cloud.silique.fr/stove/rougail-tutorials/raw/tag/v1.1_002/firefox/00-proxy.yml
    :language: yaml
-   :caption: A Rougail dictionnary file with a variable and a description
+   :caption: A Rougail structure file with a variable and a description
    :name: RougailStructFirstVariableDescription
 
 .. 
@@ -120,22 +141,45 @@ Let's add a variable's description, which is not mandatory but which is a good p
 
 :tutorial:`Download this file from the rougail-tutorials git repository <src/tag/v1.1_002/firefox/00-proxy.yml>`
 
-.. type-along:: how to set a value -- the default value
+You have two way to define a variable's description: 
 
-We need to set a value to this `proxy_mode` variable. A first way to do it is *to set a value by default*. 
+- the verbose way:
+
+  .. code-block:: yaml
+  
+      proxy_mode:  
+        description: Configure Proxy Access to the Internet
+
+
+- or the compact way, using the "`#`" YAML notation:
+
+  .. code-block:: yaml
+
+      proxy_mode:  # Configure Proxy Access to the Internet
+
+Set a default value
+---------------------
+
+.. type-along:: For those who follow the tutorial with the help of the git repository
+
+    Now you need to checkout the `v1.1_003` version::
+     
+          git checkout v1.1_003
+
+We will learn different ways to set a value, the first way is setting a *default* value. 
 
 .. glossary::
 
     default value
         
-        A default value is a variable value that is predefined, that is, this value is placed 
+        A default value is a variable value that is predefined, that's why this value is placed 
         right in the structure file.
 
-So let's define a variable with a description -- **and a default value**
+Let's add a default value to this `proxy_mode` variable. 
 
 .. extinclude:: https://forge.cloud.silique.fr/stove/rougail-tutorials/raw/tag/v1.1_003/firefox/00-proxy.yml
     :language: yaml
-    :caption: A rougail dictionnary file with a default value for the variable
+    :caption: A rougail structure file with a default value for the variable
     :name: RougailDictionaryVariableDefault
 
 ..
@@ -144,12 +188,13 @@ So let's define a variable with a description -- **and a default value**
 
 :tutorial:`Download this file from the rougail-tutorials git repository <src/tag/v1.1_003/firefox/00-proxy.yml>`
 
-.. type-along:: how to set a value -- the assignment
+.. admonition:: how to set a value -- the assignment
 
-    A default value has been set, great. Now how do I assign a value to a variable?
+    A default value has been set, great. This raises a question about what a normal value is.
 
-The different rougail roles and the default values
+    Now then how can I assign a normal value to a variable?
-------------------------------------------------------
+
+.. type-along:: The different rougail roles and the default values
 
 So far we have only talked about the one that writes the :term:`structure files <structure file>`\ . It's *role* is called the integrator's role.
 
@@ -256,7 +301,7 @@ In our firefox use case, the real type of the `proxy_mode` variable will be now
 .. extinclude:: https://forge.cloud.silique.fr/stove/rougail-tutorials/raw/tag/v1.1_004/firefox/00-proxy.yml
    :linenos:
    :language: yaml
-   :caption: The real :file:`firefox/proxy.yml` Rougail dictionnary file with a choice type
+   :caption: The real :file:`firefox/proxy.yml` Rougail structure file with a choice type
    :name: RougailDictionaryChoiceType
 
 ..
@@ -339,7 +384,7 @@ We have the list of the possible (authorized) values:
     .. extinclude:: https://forge.cloud.silique.fr/stove/rougail-tutorials/raw/tag/v1.1_004/firefox/00-proxy.yml
        :linenos:
        :language: yaml
-       :caption: A Rougail dictionnary file with a variable named `proxy_mode`, with a default value.
+       :caption: A Rougail structure file with a variable named `proxy_mode`, with a default value.
 
 ..