feat(imperative): add PixelShuffle to module.__init__.py

imperative/python/megengine/module/__init__.py

@@ -33,6 +33,7 @@ from .lrn import LocalResponseNorm
 from .module import Module
 from .normalization import GroupNorm, InstanceNorm, LayerNorm
 from .padding import Pad
+from .pixel_shuffle import PixelShuffle
 from .pooling import AvgPool2d, MaxPool2d
 from .quant_dequant import DequantStub, QuantStub
 from .sequential import Sequential