Revert "Use default help formatter"

This reverts commit 00e1376.

I thought this was unnecessary, but it is needed for --version

Author: rrthomas

nancy/__init__.py

@@ -716,7 +716,8 @@ async def real_main(argv: list[str] = sys.argv[1:]) -> None:
     # Read and process arguments
     parser = argparse.ArgumentParser(
         description="A simple templating system.",
-        epilog=f"The INPUT-PATH is a '{os.path.pathsep}'-separated list; the inputs are merged "
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        epilog=f"The INPUT-PATH is a '{os.path.pathsep}'-separated list; the inputs are merged\n"
         + "in left-to-right order.",
     )
     parser.add_argument(