Add to forward sampler release notes
* `ForwardSampler`
* Samples from the prior of a bayesian network. The network cannot have observations that are dependent on random variables.
* It's accessible from the `Keanu` factory like so: `Keanu.Sampling.Forward.withDefaultConfig()`
+ * There is a togglabe option to record the log prob of each sample. This is disabled by default for performance reasons.
### Python
