**New Features**
* A new module was created to export basic mathematical quantities such as `lb`, `ub`, `c` vectors and the `A` matrix. Use it with the `matrices` accessor in `linopy.Model`.
* For `Constraints`` and `Variables`` a `ipython` autocompletion function for getting items was added.
* Inplace updates for constraints are now more flexible.
* AnonymousConstraint can now built from comparison operations of variables with constants, e.g. `x >= 5`.
* The `Model.add_constraints` function now support input of type `ScalarVariable`, `ScalarLinearExpression` and `ScalarConstraint`.
* Terms with zero coefficient are now filtered out before writing to file to avoid unnecessary overhead.
* The function `sanitize_zeros` was added to `Constraints`. Use this to filter out zero coefficient terms.
**Bug Fixes**
* Solving with `gurobi` and `io_api="direct"` lead to wrong objective assignment if the objective contained non-unique variables. This is fixed in this version.