add docstring

Author: InvincibleRMC

test-data/pybind11_fixtures/expected_stubs_with_docs/pybind11_fixtures/demo.pyi

@@ -6,6 +6,7 @@ PI: float
 __version__: str
 
 class Color(enum.Enum):
+    """Color Enum"""
     __new__: ClassVar[Callable] = ...
     GREEN = 1
     RED = 0

test-data/pybind11_fixtures/src/main.cpp

@@ -236,7 +236,7 @@ void bind_demo(py::module& m) {
   py::class_<Point> pyPoint(m, "Point");
   py::enum_<Point::LengthUnit> pyLengthUnit(pyPoint, "LengthUnit");
   py::enum_<Point::AngleUnit> pyAngleUnit(pyPoint, "AngleUnit");
-  py::native_enum<Color>(m, "Color", "enum.Enum")
+  py::native_enum<Color>(m, "Color", "enum.Enum", "Color Enum")
     .value("RED", Color::RED)
     .value("GREEN", Color::GREEN)
     .finalize();