codespell_lib/_codespell.py: read additional args from file with with @<path>.

Author: julian-smith-artifex-com

codespell_lib/_codespell.py

@@ -388,7 +388,10 @@ def _supports_ansi_colors() -> bool:
 def parse_options(
     args: Sequence[str],
 ) -> tuple[argparse.Namespace, argparse.ArgumentParser, list[str]]:
-    parser = argparse.ArgumentParser(formatter_class=NewlineHelpFormatter)
+    parser = argparse.ArgumentParser(
+        formatter_class=NewlineHelpFormatter,
+        fromfile_prefix_chars='@',
+    )
 
     parser.set_defaults(colors=_supports_ansi_colors())
     parser.add_argument("--version", action="version", version=VERSION)