Fix django-wiki demo URL.

README.md

@@ -1385,7 +1385,7 @@ See also [Documentation Generators](#documentation-generators), [Wikimatrix](htt
 
 - [BookStack](https://www.bookstackapp.com/) - BookStack is a simple, self-hosted, easy-to-use platform for organizing and storing information. It allows for documentation to be stored in a book like fashion. ([Demo](https://www.bookstackapp.com/#demo), [Source Code](https://github.com/ssddanbrown/BookStack)) `MIT` `PHP`
 - [Cowyo](https://github.com/schollz/cowyo) - Cowyo is a feature-rich wiki for minimalists. ([Demo](https://cowyo.com)) `MIT` `Go`
-- [django-wiki](https://github.com/django-wiki/django-wiki) - Wiki system with complex functionality for simple integration and a superb interface. Store your knowledge with style: Use django models. ([Demo](https://demo.django.wiki/)) `GPL-3.0` `Python`
+- [django-wiki](https://github.com/django-wiki/django-wiki) - Wiki system with complex functionality for simple integration and a superb interface. Store your knowledge with style: Use django models. ([Demo](https://demo.django-wiki.org/)) `GPL-3.0` `Python`
 - [Documize](https://documize.com) - Modern Docs + Wiki software with built-in workflow, single binary executable, just bring MySQL/Percona. ([Source Code](https://github.com/documize/community)) `AGPL-3.0` `Go`
 - [Dokuwiki](https://www.dokuwiki.org/DokuWiki) - Easy to use, lightweight, standards-compliant wiki engine with a simple syntax allowing reading the data outside the wiki. All data is stored in plain files, therefore no database is required. ([Source Code](https://github.com/splitbrain/dokuwiki)) `GPL-2.0` `PHP`
 - [Gitit](https://github.com/jgm/gitit) - Wiki program that stores pages and uploaded files in a git repository, which can then be modified using the VCS command line tools or the wiki's web interface. `GPL-2.0` `Haskell`