readme: badges

README.md

@@ -1,3 +1,7 @@
+[![AGPL](https://img.shields.io/badge/License-AGPL%20v3-blue.svg)](https://en.wikipedia.org/wiki/Affero_General_Public_License)
+[![project chat](https://img.shields.io/badge/zulip-join_chat-brightgreen.svg)](https://nixos.zulipchat.com/#narrow/stream/413948-nixos)
+[![Harmeless Code of Conduct](https://img.shields.io/badge/harmless-8A2BE2)](https://srid.ca/coc "This project follows the 'Harmlessness Code of Conduct'")
+
 This repository contains the Nix / NixOS configuration for all of my systems. See [nixos-flake](https://community.flake.parts/nixos-flake) if you want to create your own configuration from scratch.
 
 ## Setup