Move to Deno+Bunny.net, add a way to test webring locally.

src/random.ts

@@ -0,0 +1,13 @@
+import { randomEntry } from './webring.ts';
+
+export function redirectRandom(req: Request) {
+  const url = randomEntry()?.url ?? new URL(req.url).origin;
+
+  return new Response('', {
+    status: 303,
+    headers: {
+      location: url,
+      'cache-control': 'no-cache, no-store, no-transform',
+    },
+  });
+}