make the "Written at" more legible

src/main.rs

@@ -598,7 +598,7 @@ fn output_html(
                 body {
                     h1 { (title) }
                     img src="hero.webp" width="700" height="233" {}
-                    p { "Written at: " (now.to_rfc3339()) }
+                    p { "Written at: " (now.format("%F %T")) }
                     @for entry in html_list {
                         (entry)
                     }