add observability overview page (#362)

Author: mdbirnstiehl

solutions/observability.md

@@ -6,9 +6,25 @@ mapped_urls:
 
 # Observability
 
-% What needs to be done: Align serverless/stateful
+{{observability}} accelerates problem resolution with open, flexible, and unified observability powered by advanced machine learning and analytics. Elastic ingests all operational and business telemetry and correlates for faster root cause detection.
 
-% Use migrated content from existing pages that map to this page:
 
-% - [ ] ./raw-migrated-files/docs-content/serverless/what-is-observability-serverless.md
-% - [ ] ./raw-migrated-files/observability-docs/observability/index.md
+## Get started [_get_started]
+
+* [**Get started**](observability/get-started.md): Discover more about our observability features and how to get started.
+* [**Quickstart: Monitor hosts with Elastic Agent**](observability/get-started/quickstart-monitor-hosts-with-elastic-agent.md): Scan your host to detect and collect logs and metrics.
+* [**Quickstart: Monitor your Kubernetes cluster with Elastic Agent**](observability/get-started/quickstart-monitor-kubernetes-cluster-with-elastic-agent.md): Create the Kubernetes resources that are required to monitor your cluster infrastructure.
+* [**Get started with Logs**](observability/logs/get-started-with-system-logs.md): Add your log data to {{obs-serverless}} and start exploring your logs.
+* [**Get started with traces and APM**](observability/apps/get-started-with-apm.md): Collect Application Performance Monitoring (APM) data and visualize it in real time.
+* [**Get started with metrics**](observability/infra-and-hosts/get-started-with-system-metrics.md): Add your metrics data to {{obs-serverless}} and visualize it in real time.
+
+
+## How to [_how_to]
+
+* [**Explore log data**](observability/logs/logs-explorer.md): Use Discover to explore your log data.
+* [**Trigger alerts and triage problems**](../solutions/observability/incident-management/create-manage-rules.md): Create rules to detect complex conditions and trigger alerts.
+* [**Track and deliver on your SLOs**](observability/incident-management/service-level-objectives-slos.md): Measure key metrics important to the business.
+* [**Detect anomalies and spikes**](../explore-analyze/machine-learning/anomaly-detection.md): Find unusual behavior in time series data.
+* [**Monitor application performance**](observability/apps/application-performance-monitoring-apm.md): Monitor your software services and applications in real time.
+* [**Integrate with OpenTelemetry**](observability/apps/use-opentelemetry-with-apm.md): Reuse existing APM instrumentation to capture logs, traces, and metrics.
+* [**Monitor your hosts and services**](observability/infra-and-hosts/analyze-compare-hosts.md): Get a metrics-driven view of your hosts backed by an interface called Lens.