Add user created and last seen on (#19)

- Updated view models / interfaces per F# naming guidelines

src/MyWebLog.Data/Utils.fs

@@ -9,13 +9,13 @@ open MyWebLog.ViewModels
 let rec orderByHierarchy (cats : Category list) parentId slugBase parentNames = seq {
     for cat in cats |> List.filter (fun c -> c.parentId = parentId) do
         let fullSlug = (match slugBase with Some it -> $"{it}/" | None -> "") + cat.slug
-        { id          = CategoryId.toString cat.id
-          slug        = fullSlug
-          name        = cat.name
-          description = cat.description
-          parentNames = Array.ofList parentNames
+        { Id          = CategoryId.toString cat.id
+          Slug        = fullSlug
+          Name        = cat.name
+          Description = cat.description
+          ParentNames = Array.ofList parentNames
           // Post counts are filled on a second pass
-          postCount   = 0
+          PostCount   = 0
         }
         yield! orderByHierarchy cats (Some cat.id) (Some fullSlug) ([ cat.name ] |> List.append parentNames)
 }