Add clang format and corresponding ci action

.clang-format

@@ -0,0 +1,28 @@
+BasedOnStyle: LLVM
+Language: Cpp
+
+IndentWidth: 4
+UseTab: Never
+#NamespaceIndentation: All
+
+PointerAlignment: Left
+AccessModifierOffset: -4
+AlwaysBreakTemplateDeclarations: true
+LambdaBodyIndentation: Signature
+
+MaxEmptyLinesToKeep: 3
+#ColumnLimit: 128
+
+CompactNamespaces: true
+FixNamespaceComments: true
+
+AllowShortFunctionsOnASingleLine: false
+AllowShortIfStatementsOnASingleLine: true
+
+AlignConsecutiveAssignments: true
+AlignConsecutiveBitFields: true
+AlignConsecutiveDeclarations: true
+AlignConsecutiveMacros: true
+
+#BraceWrapping:
+#  BeforeElse: true