add vite-plugin-llms to integrations section

[saschaseniuk]

Overview

This PR adds vite-plugin-llms to the integrations section, providing an easy way for Vite-based projects to implement the llms.txt specification.

Why this integration matters

The plugin solves several key challenges for web applications:

• Automatically serves markdown files alongside routes with .md extension
• Handles the /llms.txt file in development and production
• Works with any Vite-based framework (Vue, React, Svelte, etc.)
• Zero configuration needed to follow the specification

Change

## Integrations

Various tools and plugins are available to help integrate the llms.txt specification into your workflow:

- [`llms_txt2ctx`](https://llmstxt.org/intro.html#cli) - CLI and Python module for parsing llms.txt files and generating LLM context
- [JavaScript Implementation](./llmstxt-js.html) - Sample JavaScript implementation
- [vite-plugin-llms](https://github.com/saschaseniuk/vite-plugin-llms) - Vite plugin that serves markdown files alongside your routes following the llms.txt specification