Add minimal dashboard for the observability stack

Signed-off-by: ArthurSens <[email protected]>

Author: ArthurSens

operations/observability/mixins/self-hosted/dashboards.libsonnet

@@ -7,5 +7,6 @@
   grafanaDashboards+:: {
     'gitpod-sh-example-overview.json': (import 'dashboards/examples/overview.json'),
     'argocd.json': (import 'dashboards/argocd/argocd.json'),
+    'observability.json': (import 'dashboards/observability/observability.json'),
   },
 }