Project Maintainer self-service updates and data access rules

[RobertKielty]

Registered CNCF Project Maintainers can login to maintainer-d to

• update their record to inform the CNCF of
  • changes to their email address
  • changes to their company affiliation

Registered CNCF Project Maitnainers can view the data associated with CNCF Projects that they can already see on

https://github.com/cncf/foundation/blob/main/project-maintainers.csv

Registered CNCF Projects Maintainers are not permitted to view the email addresses of other maintainers.