Deprecate betydb.org

[dlebauer]

This should be done after v1 is released

• Archive repository
• redirect betydb.org --> gh pages (or package docs?)
• redirect docs
  • from https://pecanproject.github.io/bety-documentation to package docs
  • (data entry, data access, technical guide docs) to appropriate pages
  • betydb.org/schemas to (new, Migrate reuseable content from docs to package docs / website #17) docs of database schema
• Check LeBauer et al 2018 and docs for other links that need to be updated