Fixes parameter name

Author: ProgrammerAL

src/ProgrammerAl.Site/ProgrammerAl.Site/Pages/PresentationSlides.razor

@@ -1,5 +1,5 @@
-@page "/posts/{PostUrl}/slides/{Index:int}"
-@page "/drafts/{PostUrl}/slides/{Index:int}"
+@page "/posts/{PostUrl}/slides/{Id:int}"
+@page "/drafts/{PostUrl}/slides/{Id:int}"
 @layout EmptyLayout
 @using System.Text.Encodings.Web;
 @using ProgrammerAl.Site.Components