Add details on `--whole-window` for bindsym

Updates sway.5 to include information on the usage of the `--whole-window` option in the context of the `bindsym` command, which modifies mouse bindings to allow them to operate over the whole window instead of just the titlebar. Also includes the disclaimer about mouse bindings only working over the title bar.

Also fixes the escaping of the `BTN_LEFT` and `BTN_RIGHT` key mention.
Add notes on --border and --exclude-titlebar

Update the flags for bindcode command.

sway/sway.5.scd

@@ -282,7 +282,7 @@ runtime.
 
 		for_window <criteria> move container to output <output>
 
-*bindsym* [--release|--locked] [--input-device=<device>] [--no-warn] <key combo> <command>
+*bindsym* [--whole-window] [--border] [--exclude-titlebar] [--release] [--locked] [--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
@@ -294,11 +294,24 @@ runtime.
 	the _--no-warn_ flag.
 
 	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 _BTN_RIGHT_). For the former
+	the name of the event code (ex _BTN\_LEFT_ or _BTN\_RIGHT_). For the former
 	option, the buttons will be mapped to their values in X11 (1=left, 2=middle,
 	3=right, 4=scroll up, 5=scroll down, 6=scroll left, 7=scroll right, 8=back,
 	9=forward). For the latter option, you can find the event names using
 	_libinput debug-events_.
+	
+	_--whole-window_, _--border_, and _--exclude-titlebar_ are mouse-only options
+	which affect the region in which the mouse bindings can be triggered.  By
+	default, mouse bindings are only triggered when over the title bar. With the
+	_--border_ option, the border of the window will be included in this region.
+	With the _--whole-window_ option, the cursor can be anywhere over a window
+	including the title, border, and content. _--exclude-titlebar_ can be used in
+	conjunction with any other option to specify that the titlebar should be
+	excluded from the region of consideration.
+
+	There is currently, however, no way to execute a mouse binding over a layer
+	surface (which includes the background of an empty workspace). This behaviour
+	is carried over from i3.
 
 	Example:
 ```
@@ -306,7 +319,7 @@ runtime.
 		bindsym Mod1+Shift+f exec firefox
 ```
 
-	*bindcode* [--release|--locked] [--input-device=<device>] [--no-warn] <code> <command>
+	*bindcode* [--whole-window] [--border] [--exclude-titlebar] [--release] [--locked] [--input-device=<device>] [--no-warn] <code> <command>
 	is also available for binding with key/button codes instead of key/button names.
 
 *client.<class>* <border> <background> <text> <indicator> <child_border>