fix: clarify default namespace

Author: anna-geller

content/docs/08.ui/06.settings.md

@@ -14,7 +14,7 @@ Configure Settings for Kestra.
 ## Main Configuration
 
 Options you can configure under **Main Configuration** include:
-- **Default Namespace**: e.g., `company.team`
+- **Default Namespace**: e.g., `company.team` - by default, this is empty. Once set, this will be the default namespace when creating a new flow (otherwise, we use `company.team` as a placeholder). Also, when navigating to the Flows or Executions pages, it will filter for this default namespace.
 - **Default Editor Type**: e.g., "YAML Editor" or "No Code Editor"
 - **Default Log Level**: e.g., `TRACE`
 - **Default Log Display**: Expand all, Collapse all, or Expand only failed tasks