SDL_image: Clarified which image formats require external libraries

From 0fd849a50ee043547ce8fd4ff2bbd97902d5de13 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Fri, 20 May 2022 09:19:13 -0700
Subject: [PATCH] Clarified which image formats require external libraries

---
 README.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.txt b/README.txt
index 6aa2f49..24f77db 100644
--- a/README.txt
+++ b/README.txt
@@ -5,7 +5,7 @@ The latest version of this library is available from:
 http://www.libsdl.org/projects/SDL_image/
 
 This is a simple library to load images of various formats as SDL surfaces.
-This library supports AVIF, BMP, GIF, JPEG, JPEG-XL, LBM, PCX, PNG, PNM (PPM/PGM/PBM), QOI, TGA, TIFF, WebP, XCF, XPM, and simple SVG formats.
+It can load BMP, GIF, JPEG, LBM, PCX, PNG, PNM (PPM/PGM/PBM), QOI, TGA, XCF, XPM, and simple SVG format images. It can also load AVIF, JPEG-XL, TIFF, and WebP images, depending on build options (see the note below for details.)
 
 API:
 #include "SDL_image.h"