Tutorial website doesn't exist (anymore)

When I click on the 'tutorial' link from the Cytoscape [app store](https://apps.cytoscape.org/apps/clustermaker2), I am send to this page:

http://opentutorials.cgl.ucsf.edu/index.php/Tutorial:Cluster_Maker

![image](https://user-images.githubusercontent.com/26277832/179511339-1cff2b03-4156-4189-b481-94506ba2a1a0.png)
