Please add an example for pinia in the docs

[paulrosen]

Is your feature request related to a problem? Please describe.

I spent a few hours trying to figure out how to add pinia - I searched the docs, I tried some things, I looked at the pinia docs. I even tried the AI chat bot in this page, which sent me around in circles with bad advice. Anyway, I found the solution in these issues but wish it were more obvious

Describe the solution you'd like

In the docs, have:

to install pinia when using the default vitepress theme, add the following file:

// .vitepress/theme/index.ts

import { EnhanceAppContext } from "vitepress";
import DefaultTheme from "vitepress/theme";

import { createPinia } from "pinia";

export default {
  ...DefaultTheme,
  enhanceApp(ctx: EnhanceAppContext) {
    DefaultTheme.enhanceApp(ctx);

    const pinia = createPinia();
    ctx.app.use(pinia);
  },
};

Describe alternatives you've considered

No response

Additional context

No response

Validations

• Follow our Code of Conduct
• Read the docs.
• Read the Contributing Guidelines.
• Check that there isn't already an issue that asks for the same feature to avoid creating a duplicate.

[paulrosen]

Alternately, I'm guessing that adding an app.use() line is not that unusual. Perhaps have a way in config.mts to specify it. For instance:

import { createPinia } from "pinia";
export default defineConfig({
  themeConfig: {
    use: [createPinia()],