Tacl

* Fixed Report issue that prevented non-tacl assets from being
copied to an output directory.

* Updated docs build requirements.

* Fixed catalogue relabelling to not incorrectly delete relabelled
works when mapped to an existing label that is not included in the
relabel map.

* Modified results reduce to properly handle the same witness under
different labels, namely to treat them as entirely distinct.

* Changed from deprecated pkg_resources code to importlib.resources
for handling package files.

* Changed from deprecated Bio.pairwise2 to Bio.Align.

* Added logging statement when about to output CSV results from tacl
results.

* Reworked build configuration.

* Updated corpus preparation for Taisho, both markup handling and
further splits.

* Improved performance of denormalisation sufficiently to be useful
in real cases.

* Updated templating to work with recent versions of Jinja2.

* Changed DataFrame.append to pd.concat when adding rows to a
DataFrame, to suit recent versions of pandas.

* Added the name of the missing label to the error message when
referencing a non-existent label in a catalogue.

* Added split of T1646 into "pin" divs.

* Updated build process.

* Fixed unwanted inclusion of text material within apparatus
criticus markers.

* Added ability to specify a pattern of works to return from a Corpus.

* Allowed catalogues not to be sorted when saved.