docs: fix a typo in the usage string
    
        | author | Daniel J. Lauk <daniel.lauk@gmail.com> | 
    
        | date | Mon, 09 May 2011 18:16:32 -0400 | 
    
    
        | parents | 92ba778ede62 | 
    
        | children | 2f7fcbc59b02 | 
    
        | branches/tags | (none) | 
    
        | files | t.py | 
Changes
    
--- a/t.py	Sun Oct 03 19:04:03 2010 -0400
+++ b/t.py	Mon May 09 18:16:32 2011 -0400
@@ -225,7 +225,7 @@
 
 def _build_parser():
     """Return a parser for the command-line interface."""
-    usage = "Usage: %prog [-d DIR] [-l LIST] [options] [TEXT]"
+    usage = "Usage: %prog [-t DIR] [-l LIST] [options] [TEXT]"
     parser = OptionParser(usage=usage)
 
     actions = OptionGroup(parser, "Actions",