Add StaticWebAssetContentTypeMapping example (#36117)

Author: guardrex

aspnetcore/fundamentals/static-files.md

@@ -5,7 +5,7 @@ description: Learn how to serve and secure static files and configure Map Static
 monikerRange: '>= aspnetcore-3.1'
 ms.author: wpickett
 ms.custom: mvc
-ms.date: 09/02/2025
+ms.date: 09/17/2025
 uid: fundamentals/static-files
 ---
 # Static files in ASP.NET Core
@@ -1123,16 +1123,24 @@ Property | Description
 
 Item group | Description | Metadata
 --- | ---
-`StaticWebAssetContentTypeMapping` | Maps file patterns to content types and cache headers for endpoints. | Pattern, Cache
-`StaticWebAssetFingerprintPattern` | Defines patterns for applying fingerprints to static web assets for cache busting. | Pattern, Expression
+`StaticWebAssetContentTypeMapping` | Maps file patterns to content types and cache headers for endpoints. | `Pattern`, `Cache`
+`StaticWebAssetFingerprintPattern` | Defines patterns for applying fingerprints to static web assets for cache busting. | `Pattern`, `Expression`
 
 Metadata Descriptions:
 
-* **Pattern**: A glob pattern used to match files. For `StaticWebAssetContentTypeMapping`, it matches files to determine their content type (for example, `*.js` for JavaScript files). For `StaticWebAssetFingerprintPattern`, it identifies multi-extension files that require special fingerprinting treatment (for example, `*.lib.module.js`).
+* **`Pattern`**: A glob pattern used to match files. For `StaticWebAssetContentTypeMapping`, it matches files to determine their content type (for example, `*.js` for JavaScript files). For `StaticWebAssetFingerprintPattern`, it identifies multi-extension files that require special fingerprinting treatment (for example, `*.lib.module.js`).
 
-* **Cache**: Specifies the `Cache-Control` header value for the matched content type. This controls browser caching behavior (for example, `max-age=3600, must-revalidate` for media files).
+* **`Cache`**: Specifies the `Cache-Control` header value for the matched content type. This controls browser caching behavior (for example, `max-age=3600, must-revalidate` for media files).
 
-* **Expression**: Defines how the fingerprint is inserted into the filename. The default is `#[.{fingerprint}]`, which inserts the fingerprint before the extension.
+* **`Expression`**: Defines how the fingerprint is inserted into the filename. The default is `#[.{FINGERPRINT}]`, which inserts the fingerprint (`{FINGERPRINT}` placeholder) before the extension.
+
+The following example maps the bitmap file pattern (`.bmp`) to the `image/bmp` content type with the `{CACHE HEADER}` placeholder representing the `Cache-Control` header to use for non-fingerprinted endpoints:
+
+```xml
+<ItemGroup>
+  <StaticWebAssetContentTypeMapping Include="image/bmp" Cache="{CACHE HEADER}" Pattern="*.bmp" />
+</ItemGroup>
+```
 
 ## Runtime configuration options