Save cs example into an actual project

examples/csharp/Pose.cs

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+using System.Numerics;
+
+namespace Demo
+{
+    /// <summary>
+    /// <para>
+    /// Represents a rigid transformation from one coordinate system to another. <b>NOTE: By default, unless otherwise
+    /// stated, the <c>Pose</c> of an object transforms its local space to the ambient world space. </b>
+    /// </para>
+    /// <para>
+    /// Given two <c>Pose</c>s <c>p1</c> and <c>p2</c> which transform from space A to B and from B to C respectively,
+    /// the pose <c>p2 * p1</c> transforms from A to C, and <c>p1 * v</c> transforms a vector <c>v</c> from space A to
+    /// B. A <c>Pose</c> has a rotation and a translation. The rotation is always applied first, followed by the
+    /// translation.
+    /// </para>
+    /// </summary>
+    /// <param name="rotation">The rotation of this pose.</param>
+    /// <param name="translation">The translation of this pose.</param>
+    public struct Pose(Quaternion rotation, Vector3 translation)
+    {
+        public Vector3 Translation { readonly get; set; } = translation;
+        public Quaternion Rotation { readonly get; set; } = rotation;
+
+        public static Pose Identity => new(Quaternion.Identity, Vector3.Zero);
+
+        public Pose(Vector3 translation) : this(Quaternion.Identity, translation) { }
+        public Pose(Quaternion rotation) : this(rotation, Vector3.Zero) { }
+
+        public static Vector3 operator *(Pose p, Vector3 v) => Vector3.Transform(v, p.Rotation) + p.Translation;
+        public static Pose operator *(Pose a, Pose b) => new(a.Rotation * b.Rotation, a * b.Translation);
+        public readonly Pose Inverse
+        {
+            get
+            {
+                var rotInv = Quaternion.Conjugate(Rotation);
+                return new(rotInv, -Vector3.Transform(Translation, rotInv));
+            }
+        }
+    }
+}