Show H1 tag value for page titles

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

@@ -197,7 +197,6 @@ namespace Volo.Docs.Pages.Documents.Project
 
             await SetNavigationAsync();
             SetLanguageSelectListItems();
-            SetDocumentPageTitle();
 
             return Page();
         }
@@ -472,7 +471,12 @@ namespace Volo.Docs.Pages.Documents.Project
         
         private void SetDocumentPageTitle()
         {
-            DocumentPageTitle = Navigation.FindNavigation(DocumentNameWithExtension)?.Text ?? DocumentName?.Replace("-", " ");
+            DocumentPageTitle = DocumentName?.Replace("-", " ");
+            var match = Regex.Match(Document.Content, @"#(?<PageTitle>.+)");
+            if (match.Success && match.Groups.TryGetValue("PageTitle", out var group))
+            {
+                DocumentPageTitle = Regex.Replace(group.Value, "<.*?>", string.Empty);
+            }
         }
 
         public string CreateVersionLink(VersionInfoViewModel latestVersion, string version, string documentName = null)
@@ -508,6 +512,7 @@ namespace Volo.Docs.Pages.Documents.Project
                     Document = await GetSpecificDocumentOrDefaultAsync(language);
                     DocumentLanguageCode = language;
                     DocumentNameWithExtension = Document.Name;
+                    SetDocumentPageTitle();
                     await ConvertDocumentContentToHtmlAsync();
                     return true;
                 }