Merge branch 'feature/ContentList-indexing' into develop

Exposed a new `IsIndexed` and `IndexLabel` property on the `ContentListTopicViewModel`. This provides optional support for editors to configure a topic to include a table of contents of either categories and/or items. It is up to the implementor as to whether this functionality is exposed on the `ContentList` content type or any of its derived types, as well as how it will be exposed within any templates. It is a common enough requirement, however, that including it on the model provides a lot of flexibility for expected implementations.

Author: JeremyCaney

OnTopic.ViewModels/ContentListTopicViewModel.cs

@@ -36,5 +36,36 @@ public class ContentListTopicViewModel: PageTopicViewModel {
     /// </summary>
     public TopicViewModelCollection<TopicViewModel> Categories { get; } = new();
 
+    /*==========================================================================================================================
+    | IS INDEXED?
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Provides a flag determining whether or not the content list should be indexed.
+    /// </summary>
+    /// <remarks>
+    ///   The <see cref="IsIndexed"/> property, if set, requests that the view provides a list of <see cref="ContentItems"/> or
+    ///   <see cref="Categories"/> at the top, with links to each one. This is entirely up to the discretion of the view as to
+    ///   how to implement—or even whether it's appropriate. For instance, it might not make sense on views rendering as an
+    ///   accordion or a searchable list. Nevertheless, it's a common enough feature that having it exposed as a first-party
+    ///   option helps implementors account for common scenarios. As with other properties, it won't be set if there isn't a
+    ///   corresponding attribute, and so this can easily be hidden or disabled globally via the editor.
+    /// </remarks>
+    /// <returns>True if the content list should be indexed; false otherwise.</returns>
+    public bool IsIndexed { get; set; }
+
+    /*==========================================================================================================================
+    | INDEX LABEL
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Assuming <see cref="IsIndexed"/>, determines the label to display. Defaults to <i>Contents</i>.
+    /// </summary>
+    /// <remarks>
+    ///   Often, if an indexed list of links is provided on a view, it will be preceded with a lable. The <see cref=
+    ///   "IndexLabel"/> allows that to be optionally set on a per topic basis. The default value is "Contents", though it is up
+    ///   to view implementors and editor configurations as to whether this option is exposed or honored.
+    /// </remarks>
+    /// <returns>Returns the value set; defaults to "Contents".</returns>
+    public string IndexLabel { get; set; } = "Contents";
+
   } //Class
 } //Namespace