Add Python 3.12 as documented supported version. Remove 3.11 as experimental.

Co-authored-by: Dan Braghiș <[email protected]>

Author: mark-meyer

docs/getting-started.md

@@ -18,7 +18,7 @@ poetry add --dev django-pattern-library
 We support:
 
 - Django 4.2, 5.0, 5.1
-- Python 3.9, 3.10, 3.11 (experimental)
+- Python 3.9, 3.10, 3.11, 3.12
 - Django Templates only, no Jinja support
 - Modern “evergreen” desktop and mobile browsers