add: 外部リンクにアイコンをつける

src/lib/components/Markdown.css

@@ -43,6 +43,16 @@
         }
     }
 
+    & a[target="_blank"]:after {
+        content: '';
+        display: inline-block;
+        width: .7em;
+        height: .7em;
+        vertical-align: text-top;
+        mask-image: url('data:image/svg+xml;utf-8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 -960 960 960"><path d="M200-120q-33 0-56.5-23.5T120-200v-560q0-33 23.5-56.5T200-840h280v80H200v560h560v-280h80v280q0 33-23.5 56.5T760-120H200Zm188-212-56-56 372-372H560v-80h280v280h-80v-144L388-332Z"/></svg>');
+        background-color: var(--font-color);
+    }
+
     & li {
         line-height: 1.5em;
     }

src/routes/code/[slug]/+layout.svelte

@@ -20,6 +20,10 @@
     }
 </script>
 
+<svelte:head>
+    <meta name="robots" content="noindex">
+</svelte:head>
+
 <div id='window'>
     <div class="menubar">
         <button style="background-color: rgb(255 95 87)"  aria-label="reload"     onclick={()=>{location.reload()}}></button>