Added llms.txt, llms-full.txt and llms/build.js script.

[mrdoob]

Related issue: #30774 (comment) #31933 (comment) #32660

Summary

Adds llms.txt files following the llms.txt specification to help LLMs generate correct, modern Three.js code.

What this does

• Guides LLMs to use import maps instead of old CDN patterns
• Includes current version number (@0.182.0) in import examples
• Explains when to use WebGLRenderer vs WebGPURenderer
• Provides TSL (Three.js Shading Language) documentation inline
• Generates markdown versions of all API docs for on-demand access

Files

File	Purpose
/llms.txt	Pointer to docs versions
/docs/llms.txt	Instructions + curated API links (~5KB)
/docs/llms-full.txt	Full TSL spec + categorized doc list (~125KB)
/docs/pages/*.html.md	766 API pages in markdown format
/utils/llms/build.js	Generator script

Build integration

• npm run build-llms - Generates all llms.txt files
• npm run build-docs - Now runs build-llms after JSDoc

Dependencies

• Added turndown for HTML→Markdown conversion

[mrdoob]

@sunag This PR moves wiki/TSL.md to docs/TSL.md.

[mrdoob]

@marwie Ended up doing a different approach than #32660. What do you think?

[sunag]

Amazing! 🚀

[mrdoob]

@harshpreet931 @Makio64 Looks good?

[harshpreet931]

@mrdoob looks amazing 💯

[Makio64]

My friends Claude & Gemini will be very happy with that update!

Looks good, lets test it ! Thanks!

[RenaudRohlinger]

Why not use the jsdoc to generate the md files instead? There is already an extraction steps which would fit perfectly for generating llms and md.

[marwie]

@mrdoob Thanks for driving this forward. Some thoughts:

1. I love to append a .md extension to the URL to get the markdown format like in my PR here. The change is quite small so it should be OK to add support? Alternatively a little link at the bottom of the HTML page to open the markdown file/copy markdown url comes to mind.

2. The llms.txt file should probably point to the markdown file instead of the HTML file since it's meant to be read / fetched by the LLMs right (see e.g. svelte.llms.txt or stripe.llms.txt)

3. Should there be some sitemap.xml or maybe all pages linked in the llms.txt to the individual markdown files? (maybe separated by sub-llms.txt, again as svelte does it, for addons / core / tsl, to keep the size reasonable, altough e.g. stripe also doesn't do that so maybe not an issue). Otherwise I'm wondering if these individual .md pages will even be discovered/used by an LLM?