add editorconfig

.editorconfig

@@ -0,0 +1,14 @@
+# This file is for unifying the coding style for different editors and IDEs.
+# More information at http://EditorConfig.org
+
+# Do not check for any .editorconfig files above this directory
+root = true
+
+# All files
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 2
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true