README and CHANGELOG updated

CHANGELOG.md

@@ -2,6 +2,12 @@
 
 All notable changes to this project will be documented in this file.
 
+## [2.0.0] - 2021-??-??
+## Added
+- `CObs` class added which can handle complex valued observables
+- Matrix to matrix operations like the matrix inverse now also work for complex matrices and matrices containing entries that are not `Obs` but `float` or `int`
+- `Obs` objects now have methods `is_zero` and `is_zero_within_error`
+
 ## [1.1.0] - 2021-10-11
 ### Added
 - `Corr` class added

README.md

@@ -6,7 +6,7 @@ It is based on the **gamma method** [arXiv:hep-lat/0306017](https://arxiv.org/ab
 * **treatment of slow modes** in the simulation as suggested in [arXiv:1009.5228](https://arxiv.org/abs/1009.5228)
 * coherent **error propagation** for data from **different Markov chains**
 * **non-linear fits with x- and y-errors** and exact linear error propagation based on automatic differentiation as introduced in [arXiv:1809.01289]
-* **matrix valued operations** and their error propagation based on automatic differentiation (cholesky decomposition, calculation of eigenvalues and eigenvectors, singular value decomposition...)
+* **real and complex matrix operations** and their error propagation based on automatic differentiation (cholesky decomposition, calculation of eigenvalues and eigenvectors, singular value decomposition...)
 
 There exist similar implementations of gamma method error analysis suites in
 - [Fortran](https://gitlab.ift.uam-csic.es/alberto/aderrors)