feat: add vitest testing

vitest.config.ts

@@ -0,0 +1,11 @@
+/// <reference types="vitest" />
+import { defineConfig } from "vite";
+import path from "path";
+
+export default defineConfig({
+    test: {
+        alias: {
+            "keycloakify": path.resolve(__dirname, "./src")
+        }
+    }
+});