update dependencies and fix some a11y issues

packages/frontend/src/lib/ui/ShowNote.svelte

@@ -53,7 +53,9 @@
 	{:else}
 		{#each files as file}
 			<div class="note file">
-				<b on:click={() => downloadFile(file)}>↓ {file.name}</b>
+				<button on:click={() => downloadFile(file)}>
+					<b>↓ {file.name}</b>
+				</button>
 				<small> {file.type} － {prettyBytes(file.size)}</small>
 			</div>
 		{/each}

packages/frontend/src/lib/ui/ThemeToggle.svelte

@@ -40,19 +40,19 @@
 	}
 </script>
 
-<div on:click={change}>
+<button on:click={change}>
 	<Icon class="icon" icon="contrast" />
 	{$theme}
-</div>
+</button>
 
 <style>
-	div :global(.icon) {
+	button :global(.icon) {
 		height: 1rem;
 		width: 1rem;
 		margin-right: 0.5rem;
 	}
 
-	div {
+	button {
 		display: flex;
 		flex-direction: row;
 		justify-content: flex-end;

packages/frontend/src/lib/views/Footer.svelte

@@ -7,7 +7,9 @@
 	<nav>
 		<a href="/">/home</a>
 		<a href="/about">/about</a>
-		<a href="https://github.com/cupcakearmy/cryptgeon" target="_blank" rel="noopener">/code</a>
+		<a href="https://github.com/cupcakearmy/cryptgeon" target="_blank" rel="noopener noreferrer">
+			code
+		</a>
 	</nav>
 </footer>