Add Vite playground for local development

npm run dev boots a Vite + Svelte 5 server at localhost:5173, importing
GraphiQL.svelte directly from source/library. HMR reflects changes
without a package rebuild. Points at the public Countries API by default
— swap playground/src/App.svelte for your own endpoint.

1 files changed, 9 insertions, 0 deletions

diff --git a/playground/src/main.ts b/playground/src/main.ts
new file mode 100644
index 0000000..bf39df9
--- /dev/null
+++ b/playground/src/main.ts
@@ -0,0 +1,9 @@
+import { mount } from "svelte";
+import App from "./App.svelte";
+
+const target = document.getElementById("app");
+
+if (!target)
+  throw new Error("missing #app target");
+
+mount(App, { target });