Minor markup tweaks (Sy instead of Nm).

*** 233,243 ****
  .Xr nroff 1
  and
  .Xr troff 1 ,
  the use of multi-byte characters may not be supported.
  .Sh INTERFACE STABILITY
! .Nm Obsolete Committed .
  The
  .Xr mdoc 5
  package should be used instead.
  .Sh SEE ALSO
  .Xr eqn 1 ,
--- 233,243 ----
  .Xr nroff 1
  and
  .Xr troff 1 ,
  the use of multi-byte characters may not be supported.
  .Sh INTERFACE STABILITY
! .Sy Obsolete Committed .
  The
  .Xr mdoc 5
  package should be used instead.
  .Sh SEE ALSO
  .Xr eqn 1 ,