Support node16 module resolution

The `node16` module resolution requires imports to use the `.js` file
extension in type definitions.

`@rollup/plugin-typescript` is needed to make this work with the Vite
setup used by Mermaid.

The module option for Mermaid internally is set to `nodenext`. This is
needed to support `.json` imports. Note that setting `module` to
`node16` or `nodenext` implies a matching `moduleResolution` value.

vite.config.ts

@@ -1,9 +1,9 @@
-import jison from './.vite/jisonPlugin';
+import jison from './.vite/jisonPlugin.js';
 import { defineConfig } from 'vitest/config';
 
 export default defineConfig({
   resolve: {
-    extensions: ['.jison', '.js', '.ts', '.json'],
+    extensions: [],
   },
   plugins: [jison()],
   test: {