Add coverage report and basic vitest settings

Set tests folder and coverage settings, update run commands for tests

vitest.config.js

@@ -0,0 +1,19 @@
+
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+	test: {
+		include: [
+			'tests/**/*.{test,spec}.?(c|m)[jt]s?(x)'
+		],
+		// exclude: [],
+		coverage: {
+			include: [
+				'src/',
+			],
+			exclude: [
+				'src/utils.mjs',
+			]
+		}
+	},
+});