Format codebase using djade

[johannaengland]

Now we can discuss if we prefer djade or djLint (#182) to format HTML files

Djade documentation: https://github.com/adamchainz/djade

[elfjes]

It doesn't seem to do much, does it?

[johannaengland]

It doesn't seem to do much, does it?

No, since it focuses on Django templates and not the underlying HTML

[johannaengland]

We decided to go for djLint for formatting instead since we cannot use both at the same time (due to endblock rules on the same line) and djade alone is not enough.