DOCUMENTATION: doxygen to ford

[mlee03]

As part of the full coupler subdocumentation project, FMScoupler will follow FMS and transition from Doxygen to FORD for HTML document generation.

This Issue proposes to convert all comments in Doxygenformat to FORD format where the FORD-styled comments look less "clustered" and messy in the code.

For example, the following

!> an example subroutine 
subroutine test(test_variable1, test_variable2)
    implicit none
    integer, intent(in) :: test_variable1 !< an example input variable
    integer, intent(in) :: test_variable2 !< annother example input variable 
    ....
end subroutine test

will be converted to

subroutine test(test_variable1, test_variable2)
    !! an example subroutine

    implicit none
    integer, intent(in) :: test_variable1
        !! an example input variable
    integer, intent(in) :: test_variable2
        !! another example input variable
    ....
end subroutine test