Function mish

pub fn mish<const D: usize, B>(tensor: Tensor<B, D>) -> Tensor<B, D>
where
    B: Backend,

Applies the Mish function as described in the paper in Mish: A Self Regularized Non-Monotonic Neural Activation Function.

$$ \text{Mish}(x) = x * \tanh(\text{Softplus}(x)) = \tanh\left(\log(1 + \exp(x))\right) $$