Add documentation for xkb_capslock/xkb_numlock

sway/sway-input.5.scd

@@ -33,6 +33,14 @@ For more information on these xkb configuration options, see
 *input* <identifier> xkb\_variant <variant>
 	Sets the variant of the keyboard like _dvorak_ or _colemak_.
 
+*input* <identifier> xkb\_capslock enabled|disabled
+	Enables or disables CapsLock on sway startup, the default is disabled.
+	Only meaningful if sway controls the keyboard.
+
+*input* <identifier> xkb\_numlock enabled|disabled
+	Enables or disables NumLock on sway startup, the default is enabled.
+	Only meaningful if sway controls the keyboard.
+
 ## MAPPING CONFIGURATION
 
 *input* <identifier> map\_to\_output <identifier>