Build failure due to sphinx-build

Job #5535463128 failed for ad07f211:

/builds/kalilinux/packages/django-tagulous/debian/output/source_dir/docs/changelog.rst:63: WARNING: Inline literal start-string without end-string.
Exception occurred:
  File "/usr/lib/python3/dist-packages/sphinx/ext/extlinks.py", line 108, in role
    title = caption % part
            ~~~~~~~~^~~~~~
TypeError: not all arguments converted during string formatting

There are actually a number of errors in the docs that are now not allowed by new sphinx. Upstream does have a commit which seems to address most if not all, however they have added their own theme for sphinx that is not packaged up. We could add the upstream patch, and then patch the theme to be maybe rtd which is packaged already, or we could just package up the theme...