docs: rename "UI Framework" to "AppShell" in navigation (#31)

* docs: rename "UI Framework" to "App Shell" in navigation

Update navigation title and page heading to reflect the correct
product name "App Shell" instead of "UI Framework".

Changes:
- docs/app-shell/index.md: Update page heading
- .vitepress/config/constants.ts: Update navigation title

Fixes #11000

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

* update title

---------

Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: anukiransolur

.vitepress/config/constants.ts

@@ -78,7 +78,7 @@ export const excludedSections: string[] = ["public"];
 
 // Custom title overrides for sections/folders
 export const customTitles: Record<string, string> = {
-  "app-shell": "UI Framework",
+  "app-shell": "AppShell",
   // Add more custom titles here as needed
 };
 

docs/app-shell/index.md

@@ -1,4 +1,4 @@
-# UI Framework
+# AppShell
 
 AppShell is a UI framework for building interfaces on Tailor Platform.