Fixes, new readme

Runtime/ArrayExtensions.cs

@@ -0,0 +1,24 @@
+using System;
+
+namespace Agoxandr.Utils
+{
+    public static class ArrayExtensions
+    {
+        public static T[] Append<T>(this T[] array, T item)
+        {
+            if (array == null)
+            {
+                return new T[] { item };
+            }
+
+            T[] result = new T[array.Length + 1];
+            for (int i = 0; i < array.Length; i++)
+            {
+                result[i] = array[i];
+            }
+
+            result[array.Length] = item;
+            return result;
+        }
+    }
+}