fix: reference htmx in default layout

src/AspNetCoreMvcHtmx/Layouts/_Layout.cshtml

@@ -5,6 +5,7 @@
   <meta content="width=device-width, initial-scale=1.0"
         name="viewport"/>
   <title>@ViewData["Title"] - TailwindVSA</title>
+  <script src="~/lib/htmx.org/dist/htmx.min.js"></script>
   <link asp-append-version="true"
         href="~/css/site.css"
         rel="stylesheet"/>