Add link to "Else" page

Add a link to [structure/control-structure/else](https://www.arduino.cc/reference/en/language/structure/control-structure/else/) to the *See also* section.

Author: boundmaidlea

Language/Structure/Control Structure/if.adoc

@@ -101,6 +101,7 @@ This is because C++ evaluates the statement `if (x=10)` as follows: 10 is assign
 === See also
 
 [role="language"]
+* #LANGUAGE# link:../else[else]
 
 --
 // SEE ALSO SECTION ENDS