Update docs: updated readFile version for async await

[swifty-amay]

###Changes

• Updated the depricated version of readFile method for reading files asynchronously.

• Changes
  try await req.fileio.readFile(at: "/path/to/file") { chunk in
  print(chunk) // ByteBuffer
  }
  (Depricated version)

  to

  let file = try await request.fileio.readFile(at: path, chunkSize: 16 * 1024) // 32Kb, ~5 chunks

[ptoffy]

Thanks for this! We can expand it to loop over the chunks AsyncSequence which will be what most users will do

[swifty-amay]

Thanks for the review, actually you're right, devs must also get to know how to loop over the chunks.

[ptoffy]

readContent is undefined here. Let's just keep the behaviour we had before where we simply print the ByteBuffer chunk

[swifty-amay]

Yes, you're right. Well, let me see if I can do something with this readContent, if not then I'll update this to the previous version where the chunks were being printed directly.