Add note in changelog about feature IDs in CustomShader
Add note in changelog about feature IDs in CustomShader

CesiumGS/cesium,likangning93/cesium,CesiumGS/cesium,CesiumGS/cesium,likangning93/cesium,CesiumGS/cesium,CesiumGS/cesium,likangning93/cesium,AnalyticalGraphicsInc/cesium,AnalyticalGraphicsInc/cesium,likangning93/cesium,likangning93/cesium