manpage: add references sway.5 <-> sway-input.5

sway/sway-input.5.txt

@@ -44,3 +44,8 @@ Commands
 
 **input** <identifier> tap <enabled|disabled>:
 	Enables or disables tap for specified input device.
+
+See Also
+--------
+
+**sway**(5)

sway/sway.5.txt

@@ -224,3 +224,8 @@ Currently supported attributes:
 	Compare against the workspace name for this view. Can be a regular expression.
 	If value is _focused_ then all the views on the currently focused workspace
 	matches.
+
+See Also
+--------
+
+**sway**(1) **sway-input**(5)