[src] Fix accidental xml documentation comments. (#20637)

In C# there are two ways to specify that a comment is an xml documentation comment:

1. The single-line '///''
2. The multi-line '/** ... **/'

TIL about the second one, when my upcoming tool to migrate API documentation
to xml comments complained that these members already had an xml comment.

This seems entirely accidental, so just remove/rewrite these few comments.

Also fix a few other typos, grammar mistakes, etc.

src/OpenGL/OpenTK/Math/Matrix4.cs

@@ -471,7 +471,7 @@ public static void CreateOrthographic (float width, float height, float zNear, f
 		/// <param name="height">The height of the projection volume.</param>
 		/// <param name="zNear">The near edge of the projection volume.</param>
 		/// <param name="zFar">The far edge of the projection volume.</param>
-		/// <rereturns>The resulting Matrix4 instance.</rereturns>
+		/// <returns>The resulting Matrix4 instance.</rereturns>
 		public static Matrix4 CreateOrthographic (float width, float height, float zNear, float zFar)
 		{
 			Matrix4 result;

src/OpenGL/OpenTK/Math/Matrix4d.cs

@@ -471,7 +471,7 @@ public static void CreateOrthographic (double width, double height, double zNear
 		/// <param name="height">The height of the projection volume.</param>
 		/// <param name="zNear">The near edge of the projection volume.</param>
 		/// <param name="zFar">The far edge of the projection volume.</param>
-		/// <rereturns>The resulting Matrix4d instance.</rereturns>
+		/// <returns>The resulting Matrix4d instance.</returns>
 		public static Matrix4d CreateOrthographic (double width, double height, double zNear, double zFar)
 		{
 			Matrix4d result;

src/SceneKit/SCNMatrix4.cs

@@ -580,7 +580,7 @@ public static void CreateOrthographic (pfloat width, pfloat height, pfloat zNear
 		/// <param name="height">The height of the projection volume.</param>
 		/// <param name="zNear">The near edge of the projection volume.</param>
 		/// <param name="zFar">The far edge of the projection volume.</param>
-		/// <rereturns>The resulting SCNMatrix4 instance.</rereturns>
+		/// <returns>The resulting SCNMatrix4 instance.</returns>
 		public static SCNMatrix4 CreateOrthographic (pfloat width, pfloat height, pfloat zNear, pfloat zFar)
 		{
 			SCNMatrix4 result;

src/SceneKit/SCNMatrix4_dotnet.cs

@@ -647,7 +647,7 @@ public static void CreateOrthographic (pfloat width, pfloat height, pfloat zNear
 		/// <param name="height">The height of the projection volume.</param>
 		/// <param name="zNear">The near edge of the projection volume.</param>
 		/// <param name="zFar">The far edge of the projection volume.</param>
-		/// <rereturns>The resulting SCNMatrix4 instance.</rereturns>
+		/// <returns>The resulting SCNMatrix4 instance.</returns>
 		public static SCNMatrix4 CreateOrthographic (pfloat width, pfloat height, pfloat zNear, pfloat zFar)
 		{
 			SCNMatrix4 result;
@@ -777,7 +777,7 @@ public static SCNMatrix4 CreatePerspectiveFieldOfView (pfloat fovy, pfloat aspec
 #region CreatePerspectiveOffCenter
 
 		/// <summary>
-		/// Creates an perspective projection matrix.
+		/// Creates a perspective projection matrix.
 		/// </summary>
 		/// <param name="left">Left edge of the view frustum</param>
 		/// <param name="right">Right edge of the view frustum</param>
@@ -818,7 +818,7 @@ public static void CreatePerspectiveOffCenter (pfloat left, pfloat right, pfloat
 		}
 
 		/// <summary>
-		/// Creates an perspective projection matrix.
+		/// Creates a perspective projection matrix.
 		/// </summary>
 		/// <param name="left">Left edge of the view frustum</param>
 		/// <param name="right">Right edge of the view frustum</param>
@@ -849,7 +849,7 @@ public static SCNMatrix4 CreatePerspectiveOffCenter (pfloat left, pfloat right,
 		/// <summary>
 		/// Build a scaling matrix
 		/// </summary>
-		/// <param name="scale">Single scale factor for x,y and z axes</param>
+		/// <param name="scale">Single scale factor for x, y and z axes</param>
 		/// <returns>A scaling matrix</returns>
 		public static SCNMatrix4 Scale (pfloat scale)
 		{
@@ -859,7 +859,7 @@ public static SCNMatrix4 Scale (pfloat scale)
 		/// <summary>
 		/// Build a scaling matrix
 		/// </summary>
-		/// <param name="scale">Scale factors for x,y and z axes</param>
+		/// <param name="scale">Scale factors for x, y and z axes</param>
 		/// <returns>A scaling matrix</returns>
 		public static SCNMatrix4 Scale (SCNVector3 scale)
 		{
@@ -1147,7 +1147,7 @@ static bool InvertSoftware (SCNMatrix4 matrix, out SCNMatrix4 result)
 		/// Calculate the inverse of the given matrix
 		/// </summary>
 		/// <param name="matrix">The matrix to invert</param>
-		/// <returns>The inverse of the given matrix if it has one, or the input if it is singular</returns>
+		/// <returns>The inverse of the given matrix if it has one.</returns>
 		/// <exception cref="InvalidOperationException">Thrown if the SCNMatrix4 is singular.</exception>
 		public static SCNMatrix4 Invert (SCNMatrix4 matrix)
 		{

src/SceneKit/SCNVector3.cs

@@ -238,7 +238,7 @@ public void NormalizeFast ()
 		public static readonly SCNVector3 UnitY = new SCNVector3 (0, 1, 0);
 
 		/// <summary>
-		/// /// Defines a unit-length SCNVector3 that points towards the Z-axis.
+		/// Defines a unit-length SCNVector3 that points towards the Z-axis.
 		/// </summary>
 		public static readonly SCNVector3 UnitZ = new SCNVector3 (0, 0, 1);
 
@@ -733,10 +733,10 @@ public static void BaryCentric (ref SCNVector3 a, ref SCNVector3 b, ref SCNVecto
 		#region Transform
 
 #if NET
-        /// <summary>Transform a direction vector by the given Matrix
-        /// Assumes the matrix has a right-most column of (0,0,0,1), that is the translation part is ignored.
-        /// </summary>
-        /// <param name="vec">The column vector to transform</param>
+		/// <summary>Transform a direction vector by the given Matrix
+		/// Assumes the matrix has a right-most column of (0,0,0,1), that is the translation part is ignored.
+		/// </summary>
+		/// <param name="vec">The column vector to transform</param>
 		/// <param name="mat">The desired transformation</param>
 		/// <returns>The transformed vector</returns>
 #else
@@ -754,14 +754,14 @@ public static SCNVector3 TransformVector (SCNVector3 vec, SCNMatrix4 mat)
 		}
 
 #if NET
-        /// <summary>Transform a direction vector by the given Matrix
-        /// Assumes the matrix has a right-most column of (0,0,0,1), that is the translation part is ignored.
-        /// </summary>
-        /// <param name="vec">The column vector to transform</param>
+		/// <summary>Transform a direction vector by the given matrix.
+		/// Assumes the matrix has a right-most column of (0,0,0,1), that is the translation part is ignored.
+		/// </summary>
+		/// <param name="vec">The column vector to transform</param>
 		/// <param name="mat">The desired transformation</param>
 		/// <param name="result">The transformed vector</param>
 #else
-		/// <summary>Transform a direction vector by the given Matrix
+		/// <summary>Transform a direction vector by the given matrix.
 		/// Assumes the matrix has a bottom row of (0,0,0,1), that is the translation part is ignored.
 		/// </summary>
 		/// <param name="vec">The row vector to transform</param>

src/coreanimation.cs

@@ -1854,7 +1854,7 @@ interface CAEmitterLayer {
 		[Export ("seed")]
 		int Seed { get; set; } // unsigned int
 
-		/** `emitterShape' values. **/
+		/* `emitterShape' values. */
 		[Field ("kCAEmitterLayerPoint")]
 		NSString ShapePoint { get; }
 
@@ -1873,7 +1873,7 @@ interface CAEmitterLayer {
 		[Field ("kCAEmitterLayerSphere")]
 		NSString ShapeSphere { get; }
 
-		/** `emitterMode' values. **/
+		/* `emitterMode' values. */
 		[Field ("kCAEmitterLayerPoints")]
 		NSString ModePoints { get; }
 
@@ -1886,7 +1886,7 @@ interface CAEmitterLayer {
 		[Field ("kCAEmitterLayerVolume")]
 		NSString ModeVolume { get; }
 
-		/** `renderOrder' values. **/
+		/*  `renderOrder' values. */
 		[Field ("kCAEmitterLayerUnordered")]
 		NSString RenderUnordered { get; }
 

src/healthkit.cs

@@ -2487,8 +2487,6 @@ enum HKDataTypeIdentifier {
 	[Mac (13, 0)]
 	[MacCatalyst (13, 1)]
 	enum HKCategoryTypeIdentifier {
-		/**** HKCategoryType Identifiers ****/
-
 		[Field ("HKCategoryTypeIdentifierSleepAnalysis")]
 		SleepAnalysis,
 
@@ -2810,8 +2808,6 @@ enum HKCategoryTypeIdentifier {
 	[Mac (13, 0)]
 	[MacCatalyst (13, 1)]
 	enum HKCharacteristicTypeIdentifier {
-		/**** HKCharacteristicType Identifiers ****/
-
 		[Field ("HKCharacteristicTypeIdentifierBiologicalSex")]
 		BiologicalSex,