feat: add enable_auto_save configuration option

src/config.zig

@@ -21,6 +21,8 @@ enable_format_on_save: bool = false,
 restore_last_cursor_position: bool = true,
 follow_cursor_on_buffer_switch: bool = false, //scroll cursor into view on buffer switch
 default_cursor: []const u8 = "default",
+enable_auto_save: bool = false,
+auto_save_file_types: []const []const u8 = &.{},
 
 indent_size: usize = 4,
 tab_width: usize = 8,