Bug 1617103 - Add documentation for yamllint. r=sylvestre DONTBUILD

Differential Revision: https://phabricator.services.mozilla.com/D154108

docs/code-quality/index.rst

@@ -177,7 +177,7 @@ In this document, we try to list these all tools.
      - :ref:`Fluent Lint`
      -
    * - YAML linter
+     - No
      -
-     -
+     - :ref:`yamllint`
-     -
      - https://github.com/adrienverge/yamllint

docs/code-quality/lint/linters/yamllint.rst

@@ -0,0 +1,31 @@
+yamllint
+========
+
+`yamllint <https://github.com/adrienverge/yamllint>`__ is a linter for YAML files.
+
+
+Run Locally
+-----------
+
+The mozlint integration of yamllint can be run using mach:
+
+.. parsed-literal::
+
+    $ mach lint --linter yaml <file paths>
+
+Alternatively, omit ``--linter yaml`` to run all configured linters, including
+yamllint.
+
+
+Configuration
+-------------
+
+To enable yamllint on a new directory, add the path to the include section in
+the :searchfox:`yaml.yml <tools/lint/yaml.yml>` file.
+
+
+Sources
+-------
+
+* :searchfox:`Configuration (YAML) <tools/lint/yaml.yml>`
+* :searchfox:`Source <tools/lint/yamllint_/__init__.py>`