docs: add missing GL_OES/EXT_gpu_shader5 enablement note

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
diff --git a/docs/relnotes/11.3.0.html b/docs/relnotes/11.3.0.html
index 8d6caa2..e6ed538 100644
--- a/docs/relnotes/11.3.0.html
+++ b/docs/relnotes/11.3.0.html
@@ -61,6 +61,7 @@
 <li>GL_EXT_base_instance on all drivers that support GL_ARB_base_instance</li>
 <li>GL_EXT_clip_cull_distance on all drivers that support GL_ARB_cull_distance</li>
 <li>GL_OES_draw_buffers_indexed and GL_EXT_draw_buffers_indexed on all drivers that support GL_ARB_draw_buffers_blend</li>
+<li>GL_OES_gpu_shader5 and GL_EXT_gpu_shader5 on all drivers that support GL_ARB_gpu_shader5</li>
 <li>GL_OES_sample_shading on i965, nvc0, r600, radeonsi</li>
 <li>GL_OES_sample_variables on i965, nvc0, r600, radeonsi</li>
 <li>GL_OES_shader_image_atomic on all drivers that support GL_ARB_shader_image_load_store</li>