cs: add «769. Max Chunks To Make Sorted»

URL:	https://leetcode.com/problems/max-chunks-to-make-sorted/
Signed-off-by: Matej Focko <me@mfocko.xyz>

cs/max-chunks-to-make-sorted.cs

@@ -0,0 +1,16 @@
+public class Solution {
+    public int MaxChunksToSorted(int[] arr) {
+        var chunks = 0;
+
+        var maximum = arr[0];
+        for (int i = 0; i < arr.Length; ++i) {
+            maximum = Math.Max(maximum, arr[i]);
+
+            if (maximum == i) {
+                ++chunks;
+            }
+        }
+
+        return chunks;
+    }
+}