Document complex variable support

Author: sethrj

Doc/Manual/Contents.html

@@ -853,6 +853,7 @@ <h3><a href="Fortran.html#Fortran">24 SWIG and Fortran</a></h3>
 <ul>
 <li><a href="Fortran.html#Fortran_other_integer_types">Other integer types</a>
 <li><a href="Fortran.html#Fortran_booleanlogical_values">Boolean/logical values</a>
+<li><a href="Fortran.html#Fortran_complex_numbers">Complex numbers</a>
 <li><a href="Fortran.html#Fortran_characters">Characters</a>
 <li><a href="Fortran.html#Fortran_references">References</a>
 </ul>