add format file

.clang-format

@@ -0,0 +1,19 @@
+BasedOnStyle: Google
+Language: Cpp
+UseTab: Never
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 2
+IndentWidth: 2
+AllowShortIfStatementsOnASingleLine: true
+AlwaysBreakTemplateDeclarations: true
+Standard: c++20
+BreakBeforeBraces: Attach
+NamespaceIndentation: All
+ColumnLimit: 100
+IndentPPDirectives: BeforeHash
+IndentCaseLabels: true
+IndentCaseBlocks: false
+IndentAccessModifiers: false
+IndentWrappedFunctionNames: true
+AlignTrailingComments: false
+SortIncludes: false