docs/quickstart.md: Document that safer_staticfiles replaces staticfiles (#12)

This may prevent users from running into:
> # ./manage.py runserver
> [..]
> django.core.exceptions.ImproperlyConfigured: Application labels aren't unique, duplicates: staticfiles

Author: hartwork

docs/quickstart.md

@@ -14,7 +14,7 @@ Add to installed apps following packages:
 INSTALLED_APPS = [
     # ...
     "django_components",
-    "django_components.safer_staticfiles",
+    "django_components.safer_staticfiles",  # replaces django.contrib.staticfiles
     "django_htmx",
     "livecomponents",
     # ...