Add a .editorconfig file to help contributors keep code styles (wbond#3545)

Author: taylon

.editorconfig

@@ -0,0 +1,15 @@
+# editorconfig.org
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+ident_size = 4
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.json]
+indent_style = tab
+
+[*.py]
+ident_style = space