feat: Add support for cypress and vitest

Signed-off-by: Avior <github@avior.me>

vitest.config.ts

@@ -0,0 +1,13 @@
+/// <reference types="vitest" />
+import { getViteConfig } from 'astro/config'
+import { configDefaults } from 'vitest/config'
+
+export default getViteConfig({
+	test: {
+		include: [
+			'./tests/**'
+		]
+		/* for example, use global to avoid globals imports (describe, test, expect): */
+		// globals: true,
+	},
+});