mathlib

a276716e - doc(overview,undergrad): refer to `affine_span` not `span_points` (#17130)

doc(overview,undergrad): refer to `affine_span` not `span_points` (#17130) As explained in the `linear_algebra.affine_space.affine_subspace` module doc string, `affine_span` is preferred over `span_points` for most purposes, so refer to `affine_span` not `span_points` in overview.yaml and undergrad.yaml.