add master README

Author: gingeleski

README.md

@@ -0,0 +1,9 @@
+# ethsec.io
+
+This is an open Ethereum security blog which lives at **https://ethsec.io**
+
+If you're interested in contributing, see the `dev` branch and/or add an issue.
+
+That branch houses the generation scripts for the static site and has the [**Open Ethereum Security Course**](https://github.com/ethereumsec/course) as a submodule.
+
+`master` branch of this project just has the static output which you see live.