docs(validator-170): ready for proofreading

docs/tutorial/types.rst

@@ -442,7 +442,7 @@ Let's run the Rougail CLI:
 ..
     rougail -m firefox/ -u yaml -yf config/02/config.yml
 
-the result is:
+The result is:
 
 .. raw:: html
   :class: output 

docs/tutorial/validators.rst

@@ -61,4 +61,67 @@ We call it a :term:`validator`.
    :language: yaml
    :caption: The :file:`firefox/60-dns_over_https.yml` with the jinja validator
 
+Here we can see that the validation code is:
+
+.. code-block:: jinja
+
+    {{ _.custom_dns_url.startswith("http://") }}
+
+
+A validator can return a string, in fact it is its default behavior.
+If it returns a string of characters, it indicates the validation error.
+
+In this case we see that we have specified the `return_type parameter`, which 
+specifies that the Jinja code shall return a boolean value.
+
+The validator's `description` parameter serves two purposes:
+
+- it does, of course, have a string function for documenting validation,
+- since the `return_type` parameter is set to boolean, 
+  the error message contains this description's string.
+
+.. type-along:: example with `http://` in the user data
+
+Now, let's try with incorrect user data, containing `http://` and not `https://`
+
+.. extinclude:: https://forge.cloud.silique.fr/stove/rougail-tutorials/raw/tag/v1.1_170/config/03/config.yml
+   :language: yaml
+   :caption: A :file:`config/03/config.yml` user data file containing `http://` 
+
+..
+    ---
+    dns_over_https:
+      enable_dns_over_https: true
+      provider: Custom
+      custom_dns_url: http://dns.net
+
+
+Let's run the Rougail CLI: 
+
+.. raw:: html
+   :class: terminal
+   :url: https://forge.cloud.silique.fr/stove/rougail-tutorials/raw/tag/v1.1_170/config/03/cmd_ro.txt
+
+..
+    rougail -m firefox/ --types types/proxy --modes_level basic standard advanced -u yaml -yf config/03/config.yml
+
+The result is:
+
+.. raw:: html
+  :class: output 
+  :url: https://forge.cloud.silique.fr/stove/rougail-tutorials/raw/tag/v1.1_170/config/03/output_ro.html
+
+The warning indicates that the validator did not allow an HTTP protocol to pass:
+
+::
+
+        ┃   the value "http://dns.net" is an invalid URL, must starts with 
+        ┃   'https://' only, it will be ignored when loading from the YAML file 
+        ┃   "config/03/config.yml"
+
+.. keypoints:: Let's review the key points
+
+   We explained the use of validations to refine the type definition of a variable.
+
+   The variable's parameter is `validator`.