feat(playground): add counter command as button example

Author: zojize

playground/discord/commands/counter.ts

@@ -0,0 +1,17 @@
+import { computed, ref } from 'vue'
+
+/**
+ * @name counter
+ * @description A simple counter command that counts button presses
+ */
+export default function counter() {
+  const count = ref(0)
+  const message = computed(() => `Count: ${count.value}`)
+
+  return reply.button(
+    '+1',
+    () => void (count.value += 1),
+    // hide the button when count reaches 5
+    { hide: computed(() => count.value >= 5) },
+  ).send(message)
+}