[bug-mailutils] Missing text in MH program "sortm --help"

[djh]

Sergey,

Will going through the gnu and traditional options for some MH documentation I 
found that the output of 

 sortm --help

I found that the output does not contain a description for the option 
"--textfield".
Only a description for "--notextfield" 

I'm not sure what exactly the  --textfield is for so can't give it a definition.

Would you please make this addtion to the MH sortm progjram.

Regards,
  Darel Henman