create a RELEASES.md file

Author: nikomatsakis

RELEASES.md

@@ -0,0 +1,24 @@
+The `chalk-engine` and `chalk-macros` crates are published to
+crates.io periodically for use by the compiler. The rest of chalk is
+not yet published, though it might be nice to publish the interpreter
+at some point.
+
+# Release 0.1.0
+
+**Tag:** `chalk-engine-v0.1.0`
+
+Initial release.
+
+# Procedure to cut a release
+
+Should make a script or something, but:
+
+```
+> // update version numbers
+> cd chalk-macros
+> cargo publish
+> cd ../chalk-ngine
+> cargo publish
+> git tag chalk-engine-vXXX
+```
+