Downgrade code style errors to warnings (#2031)

Author: BCSharp

.editorconfig

@@ -37,8 +37,8 @@ dotnet_naming_symbols.method_and_property_symbols.applicable_accessibilities = *
 dotnet_naming_style.pascal_case_style.capitalization = pascal_case
 
 # enforce some code styles
-dotnet_style_require_accessibility_modifiers = for_non_interface_members:error
-csharp_preferred_modifier_order = public, private, protected, internal, static, extern, new, virtual, abstract, sealed, override, readonly, unsafe, volatile, async:error
+dotnet_style_require_accessibility_modifiers = for_non_interface_members:warning
+csharp_preferred_modifier_order = public, private, protected, internal, file, static, extern, new, virtual, abstract, sealed, override, readonly, unsafe, required, volatile, async:warning
 
 # CA2241: Provide correct arguments to formatting methods
 dotnet_code_quality.CA2241.try_determine_additional_string_formatting_methods_automatically = true