GUIlib: Added patch note for SDL 2.0 port

From 15d70c7b93bfad2af0a5134ef5fceb808d7253d9 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Mon, 20 Jun 2022 10:31:05 -0700
Subject: [PATCH] Added patch note for SDL 2.0 port

---
 CHANGES | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/CHANGES b/CHANGES
index 7611f2f..15d58a0 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,7 @@
+2.0.0:
+Sam Lantinga - Mon Jun 20 10:30:38 PDT 2022
+ * Ported to SDL 2.0
+
 1.2.0:
 Sam Lantinga - Tue Apr  3 10:52:19 PDT 2007
  * Placed in the public domain