Update FAQ with new Hosted Repo-related content and corrections to current content

[iannesbitt]

We have plenty of content to add to the current FAQ (code section) contained in email replies and other documents.

New content:

• Emails from Ian
  • SI
  • FWC
  • GERI
  • CIB
  • KFUPM
• Security documentation
• SI questions document

Changes:

• Change HR questions to Portals
  • Can we limit permissions to specific members and/or groups for certain portals?

[mbjones]

Current preview branch (sha 07692e7) has the updated set of faqs from branch #186 and viewable: https://preview.dataone.org/faq/

I think this FAQ can be shipped as is, and so merged to main if @iannesbitt and @angiegarciaa agree. There are more changes described in issue #180 and outlined in a Google doc -- some of these are great and should be added to the ones from this issue #187.