[New] Add EditorConfig to help maintain part of coding style

.editorconfig

@@ -0,0 +1,16 @@
+root = true
+
+[*]
+tab_width = 2
+indent_size = 2
+charset = utf-8
+end_of_line = lf
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.txt]
+indent_size = false
+
+[Makefile]
+indent_style = tab