add README to manifest; see:
@@ -3,6 +3,7 @@ name = "neon"
version = "0.1.20"
authors = ["Dave Herman <dherman@mozilla.com>"]
description = "A safe abstraction layer for Node.js."
+readme = "README.md"
documentation = "https://docs.neon-bindings.com/neon/index.html"
homepage = "https://www.neon-bindings.com"
repository = "https://github.com/neon-bindings/neon"
