AssetReader is missing in the upgrade guides

[nablabla]

How can Bevy's documentation be improved?

in any of the following (not sure which)
https://bevyengine.org/learn/migration-guides/0-10-to-0-11/
https://bevyengine.org/learn/migration-guides/0-11-to-0-12/
https://bevyengine.org/learn/migration-guides/0-12-to-0-13/
there is missing the 'AssetReader'
It was completely changed since 0.10.0
See here: https://bevyengine.org/examples/Assets/custom-asset-reader/
formerly it was called AssetIo
Also the signature of the read function changed:

xpected `{async block@src\asset_server_plugin.rs:53:23: 66:5}` to be a future that resolves to `Result<Box<dyn AsyncRead + Send + Sync + Unpin>, AssetReaderError>`, but it resolves to `Result<Vec<u8>, AssetReaderError>`

It is now in WASM the same as in non-WASM

Sorry if I ask, but it took me 3 weeks to get this implemented. I am relatively new to rust and had too read into assosiated types, Send, async, Pin, move, Futures, Javascript closures, the whole bindgen and web-assembly topics
If there is someone who can help me how I adopt my read function in impl AssetReader for CustomAssetReader:

    fn read<'a>(&'a self,path: &'a Path) -> BoxedFuture<'a, Result<Box<Reader<'a>>, AssetReaderError>>	{
		// if we are on wasm then get asset by ID from asset server
		#[cfg(target_arch = "wasm32")] {
			let result = load_asset(path);
			let res = Box::pin(async move {
				// Call the asynchronous function directly
				let result = result.await;
				result.map(|data| {
						let d = data.unwrap_or_else(|| Vec::<u8>::new());
						log::info!("unwrapped: {}", data_to_string(&d));
						d
					}) // Handle None case if needed
					.map_err(|error| {
						log::info!("map-error!!!!!!!! {:?}", error);
						AssetReaderError::NotFound(path_str.into())
					})		});
			return res;
		}

This worked in bevy 0.10.0 (with the old function name of course)
It now gives me the above error, so I understand that it (something) has to implement "AsyncRead + Send + Sync + Unpin". But I don't know how. Back then I asked on the discord server but never got any anwer