[BUG] git-bisect man page description of terms command doesn't mention old/new support

It's a very small issue but it seems that git bisect terms does
support --term-old and --term-new options, however the man page says:

    git bisect terms [--term-good | --term-bad]

The description for the start subcommand does document the support for
the more general terms correctly:

    git bisect start [--term-{new,bad}=<term> --term-{old,good}=<term>]

so maybe it's worth fixing the git bisect terms documentation.

Britton