README: Note move of repository

Author: bergmark

README.md

@@ -1,7 +1,3 @@
-# fay-base
+# This package has moved
 
-[Changelog](CHANGELOG.md)
-
-This package exports Prelude, FFI and other modules which you probably want to use with [Fay](http://www.fay-lang.org).
-
-Anything essential for using the compiler, or modules exported by GHC's base can go in this package.
+fay-base has been moved into the [main Fay repository](https://github.com/faylang/fay/), please file issues and pull requests there.