functions: add '/t'

The HTML/JavaScript tools are so simple that there's no need to track
them via Git. This adds a shortcut to serve them directly from R2.

.gitignore

@@ -1 +1,2 @@
+.wrangler/
 node_modules/

functions/t/[slug].ts

@@ -0,0 +1,16 @@
+import type { EventContext } from '@cloudflare/workers-types';
+
+export async function onRequestGet({
+  params,
+}: EventContext<unknown, string, unknown>) {
+  const target = `https://pub-5f2914f703904c419629da4d1ac2436f.r2.dev/tools/${params.slug}.html`;
+  const response = await fetch(target);
+  if (response.status === 404) {
+    return new Response('Not Found', { status: 404 });
+  }
+
+  const content = await response.text();
+  return new Response(content, {
+    headers: { 'Content-Type': 'text/html' },
+  });
+}