Update docstring of safe_name()

Co-authored-by: Brian Rutledge <brian@bhrutledge.com>

Author: pablogsal

twine/package.py

@@ -48,6 +48,9 @@ def _safe_name(name: str) -> str:
     """Convert an arbitrary string to a standard distribution name.
 
     Any runs of non-alphanumeric/. characters are replaced with a single '-'.
+    
+    Copied from pkg_resources.safe_name for compatibility with warehouse.
+    See https://github.com/pypa/twine/issues/743.
     """
     return re.sub("[^A-Za-z0-9.]+", "-", name)