Update community.md
Update community.md

fix layout

Former-commit-id: dc1c1913690a7941b276ede6612a57542de8dec0 [formerly 4a4402ebf9f1590f19eb996e226d09a5ca41bbcf]
Former-commit-id: 95d1736d5e8826a4ee837dec1bde14656403147b
LibraryCarpentry/librarycarpentry.github.io,LibraryCarpentry/librarycarpentry.github.io,LibraryCarpentry/librarycarpentry.github.io