Improve changelog

ChangeLog.md

@@ -74,9 +74,12 @@ GeoMetricKL
 -----------
 
 A new posterior approximation scheme, called geometric Variational Inference
-(geoVI) was introduced. `GeoMetricKL` is analogous to `MetricGaussianKL` with
-the exception that geoVI samples are used instead of MGVI samples. For further
-details see (<https://arxiv.org/abs/2105.10470>).
+(geoVI) was introduced. `GeoMetricKL` extends `MetricGaussianKL` in the sense
+that it uses (non-linear) geoVI samples instead of (linear) MGVI samples.
+`GeoMetricKL` can be configured such that it reduces to `MetricGaussianKL`.
+`GeoMetricKL` is now used in `demos/getting_started_3.py` and a visual
+comparison to MGVI can be found in `demos/vi_visualized.py`. For further details
+see (<https://arxiv.org/abs/2105.10470>).
 
 
 LikelihoodOperator
@@ -86,7 +89,7 @@ A new subclass of `EnergyOperator` was introduced and all `EnergyOperator`s
 that are likelihoods are now `LikelihoodOperator`s. A `LikelihoodOperator`
 has to implement the function `get_transformation`, which returns a
 coordinate transformation in which the Fisher metric of the likelihood becomes
-the identity matrix.
+the identity matrix. This is needed for the `GeoMetricKL` algorithm.
 
 
 Changes since NIFTy 5