Refactor TableOfContents partial to use TocHeadings model

Updated the TableOfContents partial to accept a List<TocHeading> instead of the full IndexModel, simplifying its interface. Adjusted the Index.cshtml to pass Model.TocHeadings directly. Removed the unused TableOfContents.cshtml.cs code-behind file.

modules/docs/src/Volo.Docs.Web/Pages/Documents/Project/Index.cshtml

@@ -598,7 +598,7 @@
 
                         <div id="scroll-index" class="">
                             <nav id="toc" class="navbar index-scroll">
-                                    <partial name="TableOfContents" model="Model" />
+                                    <partial name="TableOfContents" model="Model.TocHeadings" />
                             </nav>
                             <div class="row">
                                 <div class="col p-0">

modules/docs/src/Volo.Docs.Web/Pages/Documents/Project/TableOfContents.cshtml

@@ -1,17 +1,18 @@
-@model Volo.Docs.Pages.Documents.Project.IndexModel
+@using Volo.Docs.TableOfContents
+@model List<TocHeading>
 @{
-    if (Model.TocHeadings == null ||Model.TocHeadings.Count == 0)
+    if (Model == null || Model.Count == 0)
     {
         return;
     }
 
-    var relevantHeadings = Model.TocHeadings
+    var relevantHeadings = Model
         .Where(h => h.Level is 2 or 3)
         .ToList();
 
     if (relevantHeadings.Count == 0)
     {
-        relevantHeadings = Model.TocHeadings
+        relevantHeadings = Model
             .Where(h => h.Level == 1)
             .ToList();
     }

modules/docs/src/Volo.Docs.Web/Pages/Documents/Project/TableOfContents.cshtml.cs

@@ -1,11 +0,0 @@
-using Volo.Abp.AspNetCore.Mvc.UI.RazorPages;
-
-namespace Volo.Docs.Pages.Documents.Project;
-
-public class TableOfContentsModel : AbpPageModel
-{
-    public void OnGet()
-    {
-    }
-}
-