docs: Added documentation for monitoring all namespaces

examples/all-namespaces.jsonnet

@@ -0,0 +1,18 @@
+local kp = (import 'kube-prometheus/kube-prometheus.libsonnet') +
+  (import 'kube-prometheus/kube-prometheus-all-namespaces.libsonnet') + {
+  _config+:: {
+    namespace: 'monitoring',
+
+    prometheus+:: {
+      namespaces: [],
+    },
+  },
+};
+
+{ ['00namespace-' + name]: kp.kubePrometheus[name] for name in std.objectFields(kp.kubePrometheus) } +
+{ ['0prometheus-operator-' + name]: kp.prometheusOperator[name] for name in std.objectFields(kp.prometheusOperator) } +
+{ ['node-exporter-' + name]: kp.nodeExporter[name] for name in std.objectFields(kp.nodeExporter) } +
+{ ['kube-state-metrics-' + name]: kp.kubeStateMetrics[name] for name in std.objectFields(kp.kubeStateMetrics) } +
+{ ['alertmanager-' + name]: kp.alertmanager[name] for name in std.objectFields(kp.alertmanager) } +
+{ ['prometheus-' + name]: kp.prometheus[name] for name in std.objectFields(kp.prometheus) } +
+{ ['grafana-' + name]: kp.grafana[name] for name in std.objectFields(kp.grafana) }