Update index.md
Update index.md

try this

Former-commit-id: b18dc4408bf87e1d038e7398f0a7b5d9c7c82ae4 [formerly 70a224a78688ba0f0f15ad2a44570fb411c49c74]
Former-commit-id: 64195ca7d0760c1431aca9a20b2090a0c1c0d423
LibraryCarpentry/librarycarpentry.github.io,LibraryCarpentry/librarycarpentry.github.io,LibraryCarpentry/librarycarpentry.github.io