Update frontpage.html
Update frontpage.html

add links

Former-commit-id: 60486e6e778a9be34598da540f000591a97e9443 [formerly 8a6396f86e2d2b1efbd454f9658473d3a2cf7636]
Former-commit-id: 41845ad81d70ba06f9ad04864fa40877d510e3a9
LibraryCarpentry/librarycarpentry.github.io,LibraryCarpentry/librarycarpentry.github.io,LibraryCarpentry/librarycarpentry.github.io