[Groff] Omission in -ms man page

[Robert Goulding]

The -ms macros do in fact allow equation numbering (as I discovered much to
my relief the other day, when writing up an article), but this is not
mentioned in either groff_ms (7) or the info pages on -ms.

The manpage should read something like:

.TP
.BR ".EQ [\fI\,align\/\fP|\fI\,equation label\/\fP] [\fI\,align\/\fP]" " and
" .EN
Denotes an equation, to be processed by the
.I eqn
preprocessor.
If the first optional argument is
.BR C ,
.BR L ,
or\~\c
.B I ,
it will be considered to be an
.I align
argument,
to center (the default), left-justify, or indent
the equation respectively.
Any other argument will be used as a flush-right
.I label
for the equation.
If the first argument is a
.I label ,
then a second optional argument may be used for
.I align .

Robert.