[CONTRIBUTING.md]
- In order to be able to build the documentation, the package
`sphinxcontrib-katex` also needs to be installed via pip.

[docs/guides/python_bindings.md]
- According to the matplotlib documentation [1], the second argument
to `imshow` needs to be a string describing a colormap name or an
instance of a ColorMap. An error occurred with the previously used
argument as it did not describe a defined colormap. As the argument is
optional, it can just be omitted (or replaced according to personal
style preferences).
- The relative link to the Quickstart page did not work, it has been
replaced by a doc-link according to the sphinx documentation [2].

[1] matplotlib.org/3.5.0/api/_as_gen/matplotlib.pyplot.imshow.html
[2] docs.readthedocs.io/en/stable/guides/cross-referencing-with-sphinx.html#the-doc-role

For each iterator the output will now also output the time took for the
iteration and the aggregated time from the start of the solver. Also
some information, which doesn't change are written once and not again.

Using this CartesianIndices, you can create a n-dimensional recetengular
shape and iterate over the region. This should be quite a powerful but
easy to use abstraction over the volume.

The provided free functions, can be used to visit neighbouring voxels
from a given position.

This is mostly as I've encountered the bug described
https://github.com/doctest/doctest/issues/473 this bump fixes that for
me and hopefully everyone using a new glibc version.

See changelog for version 2.4.7
https://github.com/doctest/doctest/blob/master/CHANGELOG.md#247-2021-12-10

The read and write free functions decide based on the extension given,
what format to read and write, making it a little more convenient to
quickly switch output and input formats. So it's only necessary to
change the string, rather than the string and the namespace prefix.

Add a constructor taking a format string and arguments, which are passed
to fmt::format. This makes it quite convenient to pass arguments to
exceptions, i.e. `throw Error("value should be 0, but is {}", value);`.

- use APSInt::toString(llvm::SmallString) everywhere
- create() instead of construct options parser for LLVM>=13