add .editorconfig

.editorconfig

@@ -0,0 +1,33 @@
+# EditorConfig is awesome: https://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+[*]
+max_line_length = 120
+indent_style = tab
+indent_size = 4
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+csharp_style_namespace_declarations = file_scoped:warning
+csharp_space_after_cast = true
+csharp_space_before_colon_in_inheritance_clause = true
+csharp_space_after_colon_in_inheritance_clause = true
+csharp_place_attribute_on_same_line = false
+
+[*.yml]
+indent_style = space
+indent_size = 2
+
+[*.{cs,vb}]
+dotnet_naming_rule.private_members_with_underscore.symbols = private_fields
+dotnet_naming_rule.private_members_with_underscore.style = prefix_underscore
+dotnet_naming_rule.private_members_with_underscore.severity = suggestion
+
+dotnet_naming_symbols.private_fields.applicable_kinds = field
+dotnet_naming_symbols.private_fields.applicable_accessibilities = private
+
+dotnet_naming_style.prefix_underscore.capitalization = camel_case
+dotnet_naming_style.prefix_underscore.required_prefix = _