Add initial .editorconfig file

.editorconfig

@@ -0,0 +1,20 @@
+# EditorConfig coding styles definitions. For more information about the
+# properties used in this file, please see the EditorConfig documentation:
+# http://editorconfig.org/
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = LF
+indent_size = 4
+indent_style = tab
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.{yml,json}]
+indent_size = 2
+indent_style = space
+
+[*.{md,diff}]
+trim_trailing_whitespace = false