Update sub-com.md
Update sub-com.md

fix formatting

Former-commit-id: 0aee151c5ceba303b14cfa113abb7c74ec589e38 [formerly 6485415879350935535d3259dcf02fb77f466412]
Former-commit-id: c215d5ba51c78a5f03be2a851b664aa6510ce8cb
LibraryCarpentry/librarycarpentry.github.io,LibraryCarpentry/librarycarpentry.github.io,LibraryCarpentry/librarycarpentry.github.io