pre-commit developer docs

docs/developer.rst

@@ -14,3 +14,47 @@ This process describes how to install and run the project locally, e.g. for deve
 *Nota*: command is to be executed through the terminal
 
 `pip install rougail`
+
+Code quality
+---------------
+
+We are using `pre-commit <https://pre-commit.com/>`_, there is a :file:`.pre-commit-config.yaml`
+pre-commit config file in the root's project.
+
+You need to:
+
+- install the pre-commit library::
+
+    pip install pre-commit
+
+- registrer the pre-commit git hooks with this command::
+
+    pre-commit install
+
+- launch the quality code procedure with::
+
+    pre-commit
+
+  or simply just commit your changes, pre-commit will automatically be launched.
+
+.. attention:: If an error is found, the commit will not happen.
+   You must resolve all errors that pre-commit that pre-commit points out to you before.
+
+.. note:: If you need for some reason to disable `pre-commit`, just set
+          the `PRE_COMMIT_ALLOW_NO_CONFIG` environment variable before commiting::
+
+              PRE_COMMIT_ALLOW_NO_CONFIG=1 git commit
+
+Coding standard
+------------------
+
+We use black
+
+.. code-block:: yaml
+
+  - repo: https://github.com/psf/black
+    rev: 22.10.0
+    hooks:
+      - id: black
+
+And some YAML and JSON validators.