[Bug] New versions of 'markdown' no longer include 'soft_unicode'

[Eragon615]

Describe the bug
Following your linux instructions and installing from requirements.txt gets you the latest markdown, which it seems they've removed soft_unicode from.

To Reproduce
Steps to reproduce the behaviour:

1. Follow instructions as written to install
2. Run nut.py or nut_gui.py
3. Watch it crash

Expected behaviour
It should work.

NUT version (or git hash):

• Nut: 3.3

Additional context
I fixed it by doing pip install markupsafe==2.0.1 to force an older version that still has soft_unicode. I don't know python programming very well, but if possible you should force that version in requirements.txt.