Update the README.md.

Author: kernelmethod

README.md

@@ -1,6 +1,8 @@
 # The Encryption Compendium
 This repository contains the source code for [The Encryption Compendium](https://encryptioncompendium.org), a project of [Silicon Flatirons](https://siliconflatirons.org) and the [CU Boulder TCP Department](https://www.colorado.edu/program/tcp/).
 
+**The Encryption Compendium is still under development. We welcome anyone who would like to submit an issue or a pull request to this repository.**
+
 ## Development
 See [DEVELOPMENT.md](/DEVELOPMENT.md) for more information about how to develop the site. If you'd like to open an issue or make a pull request, please refer to [CONTRIBUTING.md](/CONTRIBUTING.md) for contribution guidelines.