feat: update this highly outdated app to use latest packages and custom configs (#1)

Reviewed-on: https://codeberg.org/nhcarrigan/tingle-bot/pulls/1
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

vitest.config.ts

@@ -0,0 +1,15 @@
+import { defineConfig } from "vitest/config";
+
+export default defineConfig({
+  test: {
+    coverage: {
+      provider: "istanbul",
+      reporter: ["text", "html"],
+      all: true,
+      allowExternal: true,
+      thresholds: {
+        lines: 0,
+      },
+    },
+  },
+});