add style guide files

Author: arashbm

.clang-format

@@ -0,0 +1,11 @@
+---
+Language: Cpp
+BasedOnStyle: LLVM
+DerivePointerAlignment: false
+PointerAlignment: Left
+IndentWidth: 2
+ContinuationIndentWidth: 2
+AlignAfterOpenBracket: AlwaysBreak
+BreakTemplateDeclarations: true
+...
+

.editorconfig

@@ -0,0 +1,13 @@
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+
+# 4 space indentation
+[*.{cpp,hpp}]
+indent_style = space
+indent_size = 2