[Rd] trivial typo in man/pretty.Rd

[Martin Maechler]

>>>>> Ben Bolker <bbolker at gmail.com>
>>>>>     on Mon, 19 Mar 2018 11:57:34 -0400 writes:

    > patch against recent SVN ...
    > as far as I can tell this trivial typo has been there for 20 years:

    > https://github.com/wch/r-source/blame/ba7920a99fb2fb62b89e404e65f8b132ed4c150a/src/library/base/man/pretty.Rd

indeed, 20 years and 2 weeks today:  then it's good to fix it
finally.

Thank you Ben!
Martin

    > ===================================================================
    > --- pretty.Rd	(revision 74426)
    > +++ pretty.Rd	(working copy)
    > @@ -21,8 +21,8 @@
    > \item{min.n}{nonnegative integer giving the \emph{minimal} number of
    > intervals.  If \code{min.n == 0}, \code{pretty(.)} may return a
    > single value.}
    > -  \item{shrink.sml}{positive numeric
    > -    by a which a default scale is shrunk in the case when
    > +  \item{shrink.sml}{positive numeric factor
    > +    by which a default scale is shrunk in the case when
    > \code{range(x)} is very small (usually 0).}
    > \item{high.u.bias}{non-negative numeric, typically \eqn{> 1}.
    > The interval unit is determined as \{1,2,5,10\} times \code{b}, a