Update maintainers.md
Update maintainers.md

remove "Lesson"

Former-commit-id: 85a35bfdcd43086760b8441df8c1f5274e41d482 [formerly b3b8faba7d1cf9e6c15d9bf3d9fa458127fd5ff8]
Former-commit-id: 9a2db063e39b86b2540458287859d6871c65677f
LibraryCarpentry/librarycarpentry.github.io,LibraryCarpentry/librarycarpentry.github.io,LibraryCarpentry/librarycarpentry.github.io