chore: add health check badge (#341)

Author: matifali

.github/workflows/check.yaml

@@ -1,5 +1,5 @@
-name: Check modules on registry.coder.com
-
+name: Health
+# Check modules health on registry.coder.com
 on:
   schedule:
     - cron: "*/13 * * * *" # Runs every 13th minute

README.md

@@ -7,6 +7,7 @@
 
 [![discord](https://img.shields.io/discord/747933592273027093?label=discord)](https://discord.gg/coder)
 [![license](https://img.shields.io/github/license/coder/modules)](./LICENSE)
+[![Health](https://github.com/coder/modules/actions/workflows/check.yaml/badge.svg)](https://github.com/coder/modules/actions/workflows/check.yaml)
 
 </div>