<Please replace this paragraph by a description of what this PR does and alter the TODO-list below to what applies here. Please make a 'draft PR' to begin and then only mark it as ready for review once all the relevant points are done.>
[x] Tests added (N/A)
[x] Documentation added (N/A)
[x] Example added (in the documentation, to an existing notebook, or in a new notebook)
[x] Description in CHANGELOG.rst added (single line such as: (`#XX <https://github.com/openscm/openscm-twolayermodel/pull/XX>`_) Added feature which does something)
<Please replace this paragraph by a description of what this PR does and alter the TODO-list below to what applies here. Please make a 'draft PR' to begin and then only mark it as ready for review once all the relevant points are done.>
CHANGELOG.rst
added (single line such as:(`#XX <https://github.com/openscm/openscm-twolayermodel/pull/XX>`_) Added feature which does something
)