feat: add notes to all applications

src/content/docs/applications/shelly-plug.mdx

@@ -13,3 +13,15 @@ hero:
       link: https://gitea.alexlebens.dev/alexlebens/infrastructure/src/branch/main/clusters/cl01tl/helm/shelly-plug
       icon: right-arrow
 ---
+
+import { Aside } from '@astrojs/starlight/components';
+
+<Aside type="tip">Has an internal [Grafana Dashboard](https://grafana.alexlebens.net/goto/afit87jux375sa?orgId=1).</Aside>
+
+# Purpose
+
+Metrics from the Shelly Plug.
+
+# Notes
+
+Can provide historical wattage use of the shelly plug which the entire homelab's electricity passes through.