Add note about Texture.flipY/premultiplyAlpha properties for ImageBitmap to Texture document

docs/api/en/textures/Texture.html

@@ -189,11 +189,15 @@
 		<p>
 		False by default, which is the norm for PNG images. Set to true if the RGB values have
 		been stored premultiplied by alpha.
+		Note that this property has no effect for [link:https://developer.mozilla.org/de/docs/Web/API/ImageBitmap ImageBitmap].
+		You need to configure on bitmap creation instead. See [page:ImageBitmapLoader].
 		</p>
 
 		<h3>[property:boolean flipY]</h3>
 		<p>
 		True by default. Flips the image's Y axis to match the WebGL texture coordinate space.
+		Note that this property has no effect for [link:https://developer.mozilla.org/de/docs/Web/API/ImageBitmap ImageBitmap].
+		You need to configure on bitmap creation instead. See [page:ImageBitmapLoader].
 		</p>
 
 		<h3>[property:number unpackAlignment]</h3>

docs/api/zh/textures/Texture.html

@@ -188,11 +188,15 @@
 		<p>
 			默认为false，这是PNG图像的规范。
 			如果RGB值已被Alpha预乘，请将其设为true。
+			Note that this property has no effect for [link:https://developer.mozilla.org/de/docs/Web/API/ImageBitmap ImageBitmap].
+			You need to configure on bitmap creation instead. See [page:ImageBitmapLoader].
 		</p>
 
 		<h3>[property:boolean flipY]</h3>
 		<p>
 		默认为true。翻转图像的Y轴以匹配WebGL纹理坐标空间。
+		Note that this property has no effect for [link:https://developer.mozilla.org/de/docs/Web/API/ImageBitmap ImageBitmap].
+		You need to configure on bitmap creation instead. See [page:ImageBitmapLoader].
 		</p>
 
 		<h3>[property:number unpackAlignment]</h3>