Add Clipping helper class. Does nothing for the moment

src/UglyToad.PdfPig/Geometry/Clipping.cs

@@ -0,0 +1,23 @@
+namespace UglyToad.PdfPig.Geometry
+{
+    using UglyToad.PdfPig.Graphics;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public static class Clipping
+    {
+        const double factor = 10_000.0;
+
+        /// <summary>
+        /// DOES NOTHING
+        /// </summary>
+        /// <param name="clipping"></param>
+        /// <param name="subject"></param>
+        /// <returns></returns>
+        public static PdfPath Clip(this PdfPath clipping, PdfPath subject)
+        {
+            return subject;
+        }
+    }
+}