[IMP] contributing/git_guidelines: document [CLN] and [LINT] commit tags

closes #14657

X-original-commit: f1c74c3
Signed-off-by: Antoine Vandevenne (anv) <[email protected]>

Author: AntoineVDV

content/contributing/development/git_guidelines.rst

@@ -66,6 +66,8 @@ Tags are used to prefix your commit. They should be one of the following
 - **[CLA]** for signing the Odoo Individual Contributor License;
 - **[I18N]** for changes in translation files;
 - **[PERF]** for performance patches;
+- **[CLN]** for code cleanup;
+- **[LINT]** for linting passes;
 
 After tag comes the modified module name. Use the technical name as functional
 name may change with time. If several modules are modified, list them or use