Finish removal of V2 relics.

Author: peterhinch

README.md

@@ -1,34 +1,24 @@
 # Asynchronous programming in MicroPython
 
 CPython supports asynchronous programming via the `asyncio` library.
-MicroPython provides `uasyncio` which is a subset of this, optimised for small
+MicroPython provides `asyncio` which is a subset of this, optimised for small
 code size and high performance on bare metal targets. This repository provides
 documentation, tutorial material and code to aid in its effective use.
 
-# uasyncio version 3
+# asyncio version 3
 
-Damien has completely rewritten `uasyncio` which was released as V3.0. See
-[PR5332](https://github.com/micropython/micropython/pull/5332). This is now
-incorporated in release build V1.13 and subsequent daily builds. 
+Damien has completely rewritten `asyncio` which was released as V3.0. This is
+incorporated in all recent firmware builds. The resources in this repo may be found in the
+`v3` directory. These include a tutorial, synchronisation primitives, drivers,
+applications and demos.
 
-Resources for V3 may be found in the `v3` directory. These include a guide to
-porting applications from V2, an updated tutorial, synchronisation primitives
-and various applications and demos.
+# Concurrency
 
-V2 should now be regarded as obsolete for almost all applications with the
-possible exception mentioned below.
+Other documents provide hints on asynchronous programming techniques including
+threading and multi-core coding.
 
 ### [Go to V3 docs](./v3/README.md)
 
 # uasyncio version 2
 
-The official version 2 is entirely superseded by V3, which improves on it in
-every respect.
-
-I produced a modified `fast_io` variant of V2 which is in use for some
-specialist purposes. It enables I/O to be scheduled at high priority. Currently
-this schedules I/O significantly faster than V3; the maintainers plan to
-improve `uasyncio` I/O scheduling. When this is complete I intend to delete all
-V2 material.
-
-All V2 resources are in the V2 subdirectory: [see this README](./v2/README.md).
+This is obsolete: code and docs have been removed.