Update README to accomodate recent nclx enum changes

README.md

diff --git a/README.md b/README.md
index d62e82d..488ff09 100644
--- a/README.md
+++ b/README.md
@@ -254,7 +254,7 @@
 // Optional: Set color profile based on NCLX box
 avifNclxColorProfile nclx;
 nclx.colourPrimaries = AVIF_NCLX_COLOUR_PRIMARIES_BT709;
-nclx.transferCharacteristics = AVIF_NCLX_TRANSFER_CHARACTERISTICS_GAMMA22;
+nclx.transferCharacteristics = AVIF_NCLX_TRANSFER_CHARACTERISTICS_SRGB;
 nclx.matrixCoefficients = AVIF_NCLX_MATRIX_COEFFICIENTS_BT709;
 nclx.fullRangeFlag = AVIF_NCLX_FULL_RANGE;
 avifImageSetProfileNCLX(image, &nclx);