feat: add signatures for broadcast_shapes

Author: kgryte

signatures/manipulation/broadcast_shapes.md

@@ -0,0 +1,43 @@
+# broadcast_shapes
+
+## NumPy
+
+```
+numpy.broadcast_shapes(*args) → Tuple
+```
+
+## CuPy
+
+```
+
+```
+
+## dask.array
+
+Appears to support for not in docs: <https://github.com/dask/dask/issues/11433>
+
+```
+dask.array.broadcast_shapes(*args) → Tuple
+```
+
+## JAX
+
+```
+jax.numpy.broadcast_shapes(*shapes) → Tuple
+```
+
+## PyTorch
+
+```
+torch.broadcast_shapes(*shapes) → Size
+```
+
+## TensorFlow
+
+```
+tf.broadcast_static_shape(shape_x, shape_y) → TensorShape
+```
+
+```
+tf.broadcast_dynamic_shape(shape_x, shape_y) → Tensor
+```