Wrong deescription on iostat(2) for pot_temp_equiv_tlcl

[tenomoto]

Describe the bug

The description for iostat(2) for pot_temp_equiv_tlcl is inconsistent with contributed.ncl. The mixing ration is multiplied by 1000 when iounit(2).eq.1, i.e. the correct description should be

• iounits(2)=0 input w are g/kg
• iounits(2)=1 input w are kg/kg

rather than vice versa as the current page.