Fills the input `Tensor`

with a (semi) orthogonal matrix, as
described in `Exact solutions to the nonlinear dynamics of learning in deep linear neural networks`

- Saxe, A. et al. (2013). The input tensor must have
at least 2 dimensions, and for tensors with more than 2 dimensions the
trailing dimensions are flattened.

## Examples

```
if (torch_is_installed()) {
w <- torch_empty(3, 5)
nn_init_orthogonal_(w)
}
#> torch_tensor
#> 0.1160 -0.2048 -0.9706 0.0430 0.0257
#> -0.7007 0.1632 -0.0854 0.4108 0.5535
#> 0.0030 0.3251 -0.0535 0.7074 -0.6253
#> [ CPUFloatType{3,5} ]
```