fix(napi/parser): fix example (#13887)

Import path in `napi/parser` example was wrong. The entry point is now `index.mjs`.

Author: overlookmotel

napi/parser/example.mjs

@@ -1,7 +1,7 @@
 import fs from 'node:fs';
 import path from 'node:path';
 import { parseArgs } from 'node:util';
-import { parseSync } from './index.js';
+import { parseSync } from './index.mjs';
 
 // usage:
 // node napi/parser/example.mjs test.ts