Add deprecation notice to README

This is prior to archiving in favour of https://github.com/haskell/haskell-language-server

See haskell/haskell-language-server#473

README.md

@@ -1,12 +1,9 @@
-# Integration with `ghcide`: the new `haskell-language-server`
+# Deprecated
 
-Currently the main development effort is focused in [integrating haskell-ide-engine](https://github.com/haskell/haskell-ide-engine/issues/1416) and [ghcide](https://github.com/digital-asset/ghcide) under a common repository:
+This repository is now an historical artifact.  It was the original LSP support for haskell, which is now provided by 
 
 https://github.com/haskell/haskell-language-server
 
-Until the new `haskell-language-server` reaches the feature level and stability of `haskell-ide-engine`, we aim to continue doing monthly releases. However, in general, bug fixes will be favored over new features and refactorings. They could be redirected to the new repo to avoid duplicated efforts.
-
-You still can contribute to improve the haskell ide experience! If you are not sure if you contribution should belong to this repo or the new one, feel free to ask in [any of the communication channels](#its-time-to-join-the-project).
 
 # Haskell IDE Engine (HIE)
 <img src="https://github.com/haskell/haskell-ide-engine/raw/master/logos/HIE_logo_512.png" width="256" style="margin:25px;" align="right"/>