Fixed a bug in the articles where an article could not change between published and unpublished

Signed-off-by: Spyros Gasteratos <morfeas3000@gmail.com>
some progress

Signed-off-by: Spyros Gasteratos <morfeas3000@gmail.com>
removed the duplicate challenge appearance from the sidebar

Signed-off-by: Spyros Gasteratos <morfeas3000@gmail.com>