Click through from procedure calls in src files

[connoraird]

To explore a codebase I often click through the src, from a procedure call to the implementation of the procedure being called. For example

call some_procedure(x, y, z)

I would click (often ⌘+click) some_procedure in the above code and then be redirected to the implementation of some_procedure to learn more. i.e.

subroutine some_procedure(x, y, z)
    implicit none
    integer, intent(inout) :: x, y, z 
   ! Some computation
end subroutine some_procedure

This sort of clicking through the src in the generated docs could be useful.