create tutorial page

site/src/components/TopNav.svelte

@@ -244,6 +244,7 @@
 			on:mouseleave="{() => open = false}"
 		>
 			<li class="hide-if-desktop" class:active="{!segment}"><a rel="prefetch" href=".">Home</a></li>
+			<li class:active="{segment === 'tutorial'}"><a rel="prefetch" href="tutorial">Tutorial</a></li>
 			<li class:active="{segment === 'guide'}"><a rel="prefetch" href="guide">Guide</a></li>
 			<li class:active="{segment === 'repl'}"><a rel="prefetch" href="repl">REPL</a></li>
 			<li class:active="{segment === 'blog'}"><a rel="prefetch" href="blog">Blog</a></li>

site/src/routes/tutorial/index.svelte

@@ -0,0 +1,5 @@
+<script>
+	// import Icon from '../../components/Icon.svelte';
+</script>
+
+<h1>Tutorial</h1>