add documentation for graph-render-mode

git-svn-id: svn://svn.oetiker.ch/rrdtool/branches/1.3@1794 a5681a0c-68f1-0310-ab6d-d61299d08faa

diff --git a/program/src/rrd_tool.c b/program/src/rrd_tool.c
index 3df092b3d4378ed33620838c8a39024ab6a040bc..2438c7f1a51a4b36ffca4dcee847d6b5abd11382 100644 (file)
--- a/program/src/rrd_tool.c
+++ b/program/src/rrd_tool.c
@@ -143,6 +143,7 @@ void PrintUsage(
            "\t\t[-m|--zoom factor]\n"
            "\t\t[-A|--alt-autoscale]\n"
            "\t\t[-M|--alt-autoscale-max]\n"
+           "\t\t[-G|--graph-render-mode {normal,mono}]\n"
            "\t\t[-R|--font-render-mode {normal,light,mono}]\n"
            "\t\t[-B|--font-smoothing-threshold size]\n"
            "\t\t[-T|--tabwidth width]\n"