Update README.rst

Author: dwmcallister

README.rst

@@ -1,3 +1,12 @@
+.. image:: https://www.repostatus.org/badges/latest/unsupported.svg
+   :alt: Project Status: Unsupported – The project has reached a stable, usable state but the author(s) have ceased all work on it. A new maintainer may be desired.
+   :target: https://www.repostatus.org/#unsupported
+
+Note: This repository has been archived. There will likely be no further development at this repo, and security vulnerabilities may be unaddressed.
+=========================================
+The repo may be cloned and used under its current license.
+
+
 C & Rust Library & Examples for Building WebAssembly Modules for NGINX Unit
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