mathlib3

714bc15f - feat(category_theory/adjunction): adjoint lifting theorems (#5118)

feat(category_theory/adjunction): adjoint lifting theorems (#5118) Proves the [adjoint lifting theorem](https://ncatlab.org/nlab/show/adjoint+lifting+theorem) and the [adjoint triangle theorem](https://ncatlab.org/nlab/show/adjoint+triangle+theorem). The intent here is for all but the last four statements in the file to be implementation.