Merge #862

862: Add docs for some missing items r=michaelkirk a=urschrei

- [x] I agree to follow the project's [code of conduct](https://github.com/georust/geo/blob/main/CODE_OF_CONDUCT.md).
- [ ] I added an entry to `CHANGES.md` if knowledge of this change could be valuable to users.
---

Last one, I promise!

Co-authored-by: Stephan Hügel <shugel@tcd.ie>

geo-types/src/lib.rs

@@ -95,7 +95,7 @@ pub trait CoordinateType: Num + Copy + NumCast + PartialOrd + Debug {}
 #[allow(deprecated)]
 impl<T: Num + Copy + NumCast + PartialOrd + Debug> CoordinateType for T {}
 
-/// The type of an x or y value of a point/coordinate.
+/// For algorithms which can use both integer **and** floating point `Point`s/`Coordinate`s
 ///
 /// Floats (`f32` and `f64`) and Integers (`u8`, `i32` etc.) implement this.
 ///
@@ -106,6 +106,7 @@ pub trait CoordNum: CoordinateType + Debug {}
 #[allow(deprecated)]
 impl<T: CoordinateType + Debug> CoordNum for T {}
 
+/// For algorithms which can only use floating point `Point`s/`Coordinate`s, like area or length calculations
 pub trait CoordFloat: CoordNum + Float {}
 impl<T: CoordNum + Float> CoordFloat for T {}
 

geo/src/geometry.rs

@@ -1 +1,2 @@
+//! This module makes all geometry types available
 pub use geo_types::geometry::*;

geo/src/lib.rs

@@ -238,11 +238,11 @@ pub mod prelude {
     pub use crate::algorithm::*;
 }
 
-/// A common numeric trait used for geo algorithms.
+/// A common numeric trait used for geo algorithms
 ///
 /// Different numeric types have different tradeoffs. `geo` strives to utilize generics to allow
 /// users to choose their numeric types. If you are writing a function which you'd like to be
-/// generic over all the numeric types supported by geo, you probably want to constraint
+/// generic over all the numeric types supported by geo, you probably want to constrain
 /// your function input to `GeoFloat`. For methods which work for integers, and not just floating
 /// point, see [`GeoNum`].
 ///
@@ -285,5 +285,6 @@ impl<T> GeoFloat for T where
 {
 }
 
+/// A trait for methods which work for both integers **and** floating point
 pub trait GeoNum: CoordNum + HasKernel {}
 impl<T> GeoNum for T where T: CoordNum + HasKernel {}