Update __main__.py

Possible fix of Issue RhetTbull/osxphotos#293

osxphotos/__main__.py

@@ -174,6 +174,10 @@ which will be rendered to substitute template fields with values from the photo.
 For example, '{created.month}' would be replaced with the month name of the photo creation date. 
 e.g. 'November'. 
 \n
+Options supporting templates may be repeated e.g., --keyword-template '{label}' 
+--keyword-template '{media_type}' to add both labels and media types to the 
+keywords.
+\n
 The general format for a template is '{TEMPLATE_FIELD[,[DEFAULT]]}'. 
 Some templates have optional modifiers in form 
 '{[[DELIM]+]TEMPLATE_FIELD[(PATH_SEP)][?VALUE_IF_TRUE][,[DEFAULT]]}'