Typo fixes (#48322)

* Update 08-26-august-cumulative-update-preview.md

Fix bad markup

* Update toc.yml

Add the missing "preview" to "August 2025 cumulative update."

Author: skycommand

docs/framework/release-notes/2025/08-26-august-cumulative-update-preview.md

@@ -5,8 +5,8 @@ ms.date: 08/26/2025
 ---
 # August 2025 cumulative update preview
 
-_Released August 26, 2025_
-_Update August 29, 2025 to include Windows 11, version 24H2
+_Released August 26, 2025_  
+_Update August 29, 2025 to include Windows 11, version 24H2_
 
 ## Summary of what's new in this release
 

docs/framework/toc.yml

@@ -699,7 +699,7 @@ items:
       href: release-notes/2025/04-22-april-cumulative-update-preview.md
     - name: July 2025 cumulative update
       href: release-notes/2025/07-08-july-cumulative-update.md
-    - name: August 2025 cumulative update
+    - name: August 2025 cumulative update preview
       href: release-notes/2025/08-26-august-cumulative-update-preview.md
     - name: September 2025 cumulative update
       href: release-notes/2025/09-09-september-cumulative-update.md