Add docs for CosmosDB preview emulator

Fix #2376

Author: eerhardt

docs/database/includes/cosmos-app-host.md

@@ -231,3 +231,27 @@ var cosmos = builder.AddAzureCosmosDB("cosmos-db").RunAsEmulator(
 ```
 
 The preceding code configures the Cosmos DB emulator container to have a partition count of `100`. This is a shorthand for setting the `AZURE_COSMOS_EMULATOR_PARTITION_COUNT` environment variable.
+
+#### Use Linux-based emulator (preview)
+
+The [next generation of the Azure Cosmos DB emulator](/azure/cosmos-db/emulator-linux) is entirely Linux-based and is available as a Docker container. It supports running on a wide variety of processors and operating systems.
+
+To use the preview version of the Cosmos DB emulator, call the <xref:Aspire.Hosting.AzureCosmosExtensions.RunAsPreviewEmulator*> method. Since this feature is in preview, you need to explicitly opt into the preview feature by suppressing the `ASPIRECOSMOSDB001` experimental diagnostic.
+
+The preview emulator also supports exposing a "Data Explorer" endpoint which allows you to view the data stored in the Cosmos DB emulator via a web UI. To enable the Data Explorer, call the <xref:Aspire.Hosting.AzureCosmosExtensions.WithDataExplorer*> method.
+
+```csharp
+#pragma warning disable ASPIRECOSMOSDB001
+
+var builder = DistributedApplication.CreateBuilder(args);
+
+var cosmos = builder.AddAzureCosmosDB("cosmos-db").RunAsPreviewEmulator(
+                     emulator =>
+                     {
+                         emulator.WithDataExplorer();
+                     });
+
+// After adding all resources, run the app...
+```
+
+The preceding code configures the Linux-based preview Cosmos DB emulator container, with the Data Explorer endpoint, to use at run time.

docs/diagnostics/overview.md

@@ -74,3 +74,25 @@ Alternatively, you can suppress this diagnostic with preprocessor directive by a
         // API that is causing the warning.
 #pragma warning restore ASPIREHOSTINGPYTHON001
 ```
+
+## ASPIRECOSMOSDB001
+
+<span id="ASPIRECOSMOSDB001"></span>
+
+.NET Aspire provides a way to use the CosmosDB Linux-based (preview) emulator. Since this emulator is in preview and the shape of this API is expected to change in the future, it has been marked as _Experimental_. To suppress the compiler error/warning use the following code:
+
+To suppress this diagnostic with the `SuppressMessageAttribute`, add the following code to your project file:
+
+```xml
+<PropertyGroup>
+  <NoWarn>$(NoWarn);ASPIRECOSMOSDB001</NoWarn>
+<PropertyGroup>
+```
+
+Alternatively, you can suppress this diagnostic with preprocessor directive by adding the following code to your project:
+
+```csharp
+#pragma warning disable ASPIRECOSMOSDB001
+        // API that is causing the warning.
+#pragma warning restore ASPIRECOSMOSDB001
+```