Fix typos (#514)

src/size.rs

@@ -477,7 +477,7 @@ impl<T: PartialOrd, U> Size2D<T, U> {
         T: Zero,
     {
         let zero = T::zero();
-        // The condition is experessed this way so that we return true in
+        // The condition is expressed this way so that we return true in
         // the presence of NaN.
         !(self.width > zero && self.height > zero)
     }

src/transform3d.rs

@@ -230,7 +230,7 @@ impl<T, Src, Dst> Transform3D<T, Src, Dst> {
     /// of a 2 by 3 matrix transformation.
     ///
     /// Components follow the column-major-column-vector notation (m41 and m42
-    /// representating the translation terms).
+    /// representing the translation terms).
     ///
     /// ```text
     /// m11  m12   0   0

src/vector.rs

@@ -2297,7 +2297,7 @@ mod vector2d {
     }
 
     #[test]
-    pub fn test_tpyed_scalar_mul() {
+    pub fn test_typed_scalar_mul() {
         let p1 = Vector2DMm::new(1.0, 2.0);
         let cm_per_mm = Scale::<f32, Mm, Cm>::new(0.1);