[plt-dev] Doc bug and fix

The documentation for command line arguments to MzScheme says:

-p ‹file› ‹u› ‹path› : requires (planet "‹file›" "‹user›" "‹pkg›")
http://docs.plt-scheme.org/reference/running-sa.html#(part._mz-cmdline)


Running mzscheme --help says:

 -p <package> : Like -e '(require (planet "<package>")'


Experiments confirm the executable is correct and the docs are wrong.
I've committed a change to fix the docs (startup.scrbl):

 @item{@FlagFirst{p} @nonterm{package} :
       @scheme[require]s @scheme[(planet @#,nontermstr{package})].

N.