bindsym: update the man page to include --to-code

sway/sway.5.scd

@@ -327,7 +327,7 @@ runtime.
 
 		for_window <criteria> move container to output <output>
 
-*bindsym* [--whole-window] [--border] [--exclude-titlebar] [--release] [--locked] [--input-device=<device>] [--no-warn] <key combo> <command>
+*bindsym* [--whole-window] [--border] [--exclude-titlebar] [--release] [--locked] [--to-code] [--input-device=<device>] [--no-warn] <key combo> <command>
 	Binds _key combo_ to execute the sway command _command_ when pressed. You
 	may use XKB key names here (*xev*(1) is a good tool for discovering these).
 	With the flag _--release_, the command is executed when the key combo is
@@ -338,6 +338,10 @@ runtime.
 	overwrite a binding, swaynag will give you a warning. To silence this, use
 	the _--no-warn_ flag.
 
+	Bindings to keysyms are layout-dependent. This can be changed with the
+	_--to-code_ flag. In this case, the keysyms will be translated into the
+	corresponding keycodes in the first configured layout.
+
 	Mouse bindings operate on the container under the cursor instead of the
 	container that has focus. Mouse buttons can either be specified in the form
 	_button[1-9]_ or by using the name of the event code (ex _BTN\_LEFT_ or