SDL_image: Added patch note for cherry-picked fixes for 2.6.1 (35986)

From 35986d4d4324f0f03a2a053269588ada507241bf Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Mon, 1 Aug 2022 08:31:35 -0700
Subject: [PATCH] Added patch note for cherry-picked fixes for 2.6.1

---
 CHANGES.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/CHANGES.txt b/CHANGES.txt
index 0719b26a..33dddc34 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,3 +1,6 @@
+2.6.1:
+ * Fixed loading grayscale PNGs when using stb_image
+
 2.6.0:
  * Added support for building with CMake
  * Added stb_image as the default backend for JPG and PNG images loading.