slight tidy

- follow-up to microsoft#46

src/markitdown/__main__.py

@@ -10,37 +10,19 @@ def main():
     parser = argparse.ArgumentParser(
         description="Convert various file formats to markdown.",
         formatter_class=argparse.RawDescriptionHelpFormatter,
-        usage="""
-SYNTAX: 
-    
-    markitdown <OPTIONAL: FILENAME>
-    If FILENAME is empty, markitdown reads from stdin.
-
-EXAMPLE:
-    
-    markitdown example.pdf
-    
-    OR
-
-    cat example.pdf | markitdown
-
-    OR 
-
-    markitdown < example.pdf
-""".strip(),
+        epilog="""examples:
+  markitdown example.pdf
+  cat example.pdf | markitdown
+  markitdown < example.pdf""",
     )
 
-    parser.add_argument("filename", nargs="?")
+    parser.add_argument(
+        "filename", nargs="?", help="if unspecified, defaults to stdin"
+    )
     args = parser.parse_args()
-
-    if args.filename is None:
-        markitdown = MarkItDown()
-        result = markitdown.convert_stream(sys.stdin.buffer)
-        print(result.text_content)
-    else:
-        markitdown = MarkItDown()
-        result = markitdown.convert(args.filename)
-        print(result.text_content)
+    markitdown = MarkItDown()
+    result = markitdown.convert(args.filename or sys.stdin.buffer)
+    print(result.text_content)
 
 
 if __name__ == "__main__":