Disable marp theme if not needed

scripts/gx-teaching

@@ -12,11 +12,18 @@ echo "basedir      = $BASEDIR"
 echo "docker_image = $DOCKER_IMAGE"
 echo "action       = $ACTION"
 
+if [ -f "$BASEDIR/.marp/theme.css" ]; then
+	DOCKER_OPT_MARP_THEME="-v $BASEDIR/.marp:/app/.marp"
+	echo "Detected Marp theme. Adding option to command line ($DOCKER_OPT_MARP_THEME)"
+fi
+
+
 docker run -it \
 	-v "$BASEDIR/docs:/app/docs" \
 	-v "$BASEDIR/slides:/app/slides" \
 	-v "$BASEDIR/_build:/app/_build" \
 	-v "$BASEDIR/mkdocs.yml:/app/mkdocs.yml" \
+	$DOCKER_OPT_MARP_THEME \
 	-v "$BASEDIR/.marp:/app/.marp" \
 	-p 5200:5200 \
 	-p 5100:5100 \