Simplified README

Author: clarus

README.md

@@ -1,11 +1,5 @@
 # IO Effects for Unix (extraction)
 Unix effects for Coq extracted programs.
 
-## Install
-Using OPAM for Coq:
-
-    opam repo add coq-stable https://github.com/coq/repo-stable.git
-    opam install coq:io-effects:unix:ocaml
-
 ## Use
 See the [io-effects-unix](https://github.com/clarus/io-effects-unix) project.