Prefer file-scoped namespaces

.editorconfig

@@ -8,7 +8,7 @@ csharp_indent_labels = one_less_than_current
 csharp_using_directive_placement = inside_namespace:silent
 csharp_prefer_simple_using_statement = true:suggestion
 csharp_prefer_braces = true:silent
-csharp_style_namespace_declarations = block_scoped:silent
+csharp_style_namespace_declarations = file_scoped:silent
 csharp_style_expression_bodied_methods = false:silent
 csharp_style_expression_bodied_constructors = false:silent
 csharp_style_expression_bodied_operators = false:silent