[Inventory] Create new Inventory docs

docs/en/serverless/inventory.mdx

@@ -0,0 +1,76 @@
+---
+slug: /serverless/observability/inventory
+title: Inventory
+description: Learn about the new Inventory experience that enables you to monitor all your entities from one single place.
+tags: [ 'serverless', 'observability', 'inventory' ]
+---
+
+import Roles from './partials/roles.mdx'
+
+<p><DocBadge template="technical preview" /></p>
+
+Inventory provides a single place where you can observe the status of your entire ecosystem of hosts, containers and services at a glance, even just from logs. From there, you can monitor and understand the health of your entities, check what needs attention and start your investigations. 
+
+<DocCallOut title="Note">
+   The new Inventory requires the Elastic Entity Model (EEM). To learn more, refer to <DocLink slug="/serverless/observability/elastic-entity-model" />.
+</DocCallOut>
+
+<DocImage url="./images/inventory-catalog.png" alt="Inventory catalog"/>
+
+Inventory is currently available for hosts, containers and services, but it will scale to support all of your entities.
+
+The Elastic Entity Model currently supports the inventory experience (as identified by `host.name`, `service.name`, and `container.id`) located in data identified by the following index patterns:
+
+- **Hosts**: Where `host.name` is set in `metrics-*`, `logs-*`, `filebeat-*`, and `metricbeat-*`
+
+- **Services**: Where `service.name` is set in `filebeat*`, `logs-*`, `metrics-apm.service_transaction.1m*`, and `metrics-apm.service_summary.1m*`
+
+- **Containers**: Where `container.id` is set in `metrics-*`, `logs-*`, `filebeat-*`, and `metricbeat-*`
+
+Inventory allows you to:
+
+- Filter for your entities to provide a high-level view of what you have leveraging your own tags and labels
+- Drill down into any host, container or services to help you understand performance
+- Debug resource bottlenecks with your service caused by their containers and the hosts they run on.
+- Easily discover all entities related to the host, container or service you are viewing by leveraging your tags/labels
+
+## Explore your entities
+
+1. In your ((observability)) project, go to **Inventory** to open the entities catalog.
+
+    If you have **Admin** privileges, the EEM will be turned on automatically. Otherwise, you need to ask someone with **Admin** privileges to turn on this feature under **Stack Management**.
+
+1. In the search bar, search for your entities by name or type, for example `entity.type:service`.
+
+For each entity, you can either view your data in Discover, or click the entity name and get a detailed view. For example, for an entity of type `service`, you get the following details:
+
+- Overview
+- Transactions
+- Dependencies
+- Errors
+- Metrics
+- Infrastructure
+- Service Map
+- Logs
+- Alerts
+- Dashboards
+
+<DocImage url="./images/entity-detailed-view.png" alt="Entity detailed view"/>
+
+If you open an entity of type `host` or `container` that does not have infrastructure data, some of the visualizations will be blank and some features on the page will not be fully populated.
+
+## Add entities to the inventory
+
+Entities are added to the inventory through one of the following approaches:
+
+**Add data** 
+- Auto-detect logs and metrics 
+    Detects hosts (with metrics and logs)
+- Kubernetes
+    Detects hosts, containers and services 
+- Elastic APM / OpenTelemetry / Synthetic Monitor
+    Detects services
+
+**Associate existing service logs**
+
+To learn how, refer to <DocLink slug="/serverless/observability/add-logs-service-name" />.

docs/en/serverless/serverless-observability.docnav.json

@@ -96,6 +96,10 @@
         }
       ]
     },
+    {
+      "label": "Inventory",
+      "slug": "/serverless/observability/inventory"
+    },
     {
       "slug": "/serverless/observability/apm",
       "classic-sources": [ "enApmGuideApmOverview" ],