Unpublish old knowledgebase at https://samvera.github.io/

[heathergreerklein]

LLMs are picking up old documentation sites as valid information, so we need to completely unpublich the old github.io knowledgebase pages. We have to be careful about doing this without disrupting other sites like the ServerlessIIF site that is also part of the github.io repo.

[morganem0]

DocIG discussed this issue in our mtg 04/21.
Our questions:

• will this ticket require special permissions, to be able to do the necessary work? We're not sure about permissions for this site.
• where should this live?
• HGK will ask M Kline at NWern U
  Assigning to HGK for followup.