Make documentation available to LLMs by using llms.txt convention

[YugoCode]

Describe the feature

It would be great to enable tools like Cursor to leverage shadcn-svelte’s documentation for generating more accurate and useful code. The Svelte team recently introduced support for LLMs (see https://svelte.dev/docs/llms) by adopting the llms.txt convention (https://llmstxt.org/), which allows LLM tools to parse documentation effectively. It would be awesome if shadcn-svelte could adopt this convention and ensure the llms.txt file stays updated whenever the documentation changes.