Add dir --output msg to README, too.

1 files changed, 5 insertions, 2 deletions

diff --git a/README.md b/README.md
index 610bae473..a979afba8 100644
--- a/README.md
+++ b/README.md
@@ -94,8 +94,11 @@ The author of the Silk icon set is Mark James.
                             more than once to load options from multiple files.
         -o, --output <file> File to output gcode to (by default, the file will be saved
                             into the same directory as the input file using the
-                            --output-filename-format to generate the filename)
-    
+                            --output-filename-format to generate the filename.) If a
+                            directory is specified for this option, the output will
+                            be saved under that directory, and the filename will be
+                            generated by --output-filename-format.
+
       Non-slicing actions (no G-code will be generated):
         --repair            Repair given STL files and save them as <name>_fixed.obj
         --cut <z>           Cut given input files at given Z (relative) and export