Don't mention GlobalCurve in doc comment

It's no longer used and I'm about to remove it.

crates/fj-kernel/src/geometry/path.rs

@@ -4,10 +4,9 @@
 //!
 //! # Implementation Note
 //!
-//! This is a bit of an in-between module. It is closely associated with curves
-//! ([`Curve`]/[`GlobalCurve`]) and [`Surface`]s, but paths are not really
-//! objects themselves, as logically speaking, they are owned and not
-//! referenced.
+//! This is a bit of an in-between module. It is closely associated with
+//! [`Curve`] and [`Surface`]s, but paths are not really objects themselves, as
+//! logically speaking, they are owned and not referenced.
 //!
 //! On the other hand, the types in this module don't follow the general style
 //! of types in `fj-math`.
@@ -16,7 +15,6 @@
 //! move to `fj-math`, maybe something else entirely will happen.
 //!
 //! [`Curve`]: crate::objects::Curve
-//! [`GlobalCurve`]: crate::objects::GlobalCurve
 //! [`Surface`]: crate::objects::Surface
 
 use fj_math::{Circle, Line, Point, Scalar, Transform, Vector};