add workshop admin role
add workshop admin role

Former-commit-id: f318082be4ca1b5f4cbdf5456aa9eaae6c1b2640 [formerly b45c8fb138d8fc13ca0839b74f5de665276d13c6]
Former-commit-id: 04c0a5e717999f5556179e4ed1ab72fdc4716fd7
LibraryCarpentry/librarycarpentry.github.io,LibraryCarpentry/librarycarpentry.github.io,LibraryCarpentry/librarycarpentry.github.io