The default `width` argument to `nice_colorbar` is changed to 8 points. This ensures visibility in subplots, especially when constrained layout is used.

Improve docstring formatting and tweak linter settings

The `slice_along_path` function has been added to `analysis.interpolate`, which enables easy interpolation along a evenly spaced path that is specified by its vertices and step size. The path can have an arbitrary number of dimensions and points.

The functions `plot_array` and `plot_array_2d` now checks if the input array coordinates are uniformly spaced. If they are not, a warning is issued and the user is informed that the plot may not be accurate.

This was causing duplicated plots.

Numbagg is now an optional dependency.