During development, following questions were posed, and subsequently,
answered:

Q #1: Should this be in uasyncio package at all? Upstream doesn't have
this. Pro: will be easier for people do discover (see e.g.
#148)

A: uasyncio diverges more and more from asyncio, so if something is
convinient for uasyncio, there's no need to look back at asyncio.

Q #2: This provides implements 2 ways to create a WS connections:
1) using start_ws_server(); 2) using wrapping existing StreamReader
and StreamWriter. History: initial prototype of course used 2). But
the idea was "it should be like the official start_server()!!1". But
then I though how to integrate it e.g. with Picoweb, and became clear
that 2) is the most flixble way. So, 1) is intended to be removed.

A: 1) was removed and is not part of the merged version of the patch.

Q #3: Uses native websocket module for read path, but has own
write path due to micropython/micropython#3396

A: So far, so good.

Q #4: Requires #227
due to micropython/micropython#3394 .

A: The prerequisite was merged.