Fix next link for first item under each category (#25658)

## Description

This fixes the wrong next link for the first page under each category:

**Before**
<img width="1371" height="324" alt="image"
src="https://github.com/user-attachments/assets/48908e43-ea2f-46c7-8a53-55b7d4f7923a"
/>


**After**
<img width="1396" height="400" alt="image"
src="https://github.com/user-attachments/assets/17535110-2720-4810-937a-a2263a139c57"
/>
<img width="1412" height="200" alt="image"
src="https://github.com/user-attachments/assets/8640026f-c0c9-4cc6-aac6-40b710b25e27"
/>

---------

Co-authored-by: Xin Zhang <[email protected]>

Author: zhangxin511

docs/docs/build/bundlers.mdx

@@ -1,5 +1,6 @@
 ---
 title: Fluid and Bundlers
+sidebar_position: 10
 ---
 
 This article describes some known issues with bundlers and answers some commonly asked questions about the Fluid

docs/docs/build/experimental-features.mdx

@@ -1,5 +1,6 @@
 ---
 title: Experimental Features
+sidebar_position: 9
 ---
 
 import { ApiLink } from "@site/src/components/shortLinks";

docs/docs/build/releases-and-apitags.mdx

@@ -1,5 +1,6 @@
 ---
 title: Fluid Releases and API Support Levels
+sidebar_position: 11
 ---
 
 ## Fluid Release Versions

docs/sidebars.ts

@@ -15,37 +15,31 @@ const sidebars: SidebarsConfig = {
 			type: "category",
 			label: "Getting Started",
 			items: [{ type: "autogenerated", dirName: "start" }],
-			link: { type: "doc", id: "start/quick-start" },
 		},
 		{
 			type: "category",
 			label: "Build With Fluid",
 			items: [{ type: "autogenerated", dirName: "build" }],
-			link: { type: "doc", id: "build/overview" },
 		},
 		{
 			type: "category",
 			label: "Testing",
 			items: [{ type: "autogenerated", dirName: "testing" }],
-			link: { type: "doc", id: "testing/tinylicious" },
 		},
 		{
 			type: "category",
 			label: "Deployment",
 			items: [{ type: "autogenerated", dirName: "deployment" }],
-			link: { type: "doc", id: "deployment/service-options" },
 		},
 		{
 			type: "category",
 			label: "Data Structures",
 			items: [{ type: "autogenerated", dirName: "data-structures" }],
-			link: { type: "doc", id: "data-structures/overview" },
 		},
 		{
 			type: "category",
 			label: "Concepts",
 			items: [{ type: "autogenerated", dirName: "concepts" }],
-			link: { type: "doc", id: "concepts/architecture" },
 		},
 		{ type: "doc", id: "faq" },
 		{ type: "doc", id: "glossary" },