Add LLM JSON Schema to Development Tools

[percymcn]

Adds LLM JSON Schema as a tool entry.

What it is: a free, client-side web tool that takes an arbitrary JSON Schema and rewrites it into the restricted dialect subset each LLM provider actually accepts for structured outputs — OpenAI, Anthropic, and Gemini. Every transform it applies is annotated with the specific provider documentation rule that requires it (e.g. OpenAI requiring additionalProperties: false and every property listed as required), and keywords a provider silently drops are flagged rather than quietly removed.

Relationship to Schema Gateway (already listed): that entry solves the same problem from the CLI/CI/hosted-API direction. This one is the zero-install case — it runs entirely in the browser with no upload, which matters when the schema is from a private codebase. They complement rather than duplicate each other.

Per CONTRIBUTING.md: the entry was added to data.yaml and the README regenerated with npm install && npm start; both files are included. npm start validated the entry against schema.json successfully. The unrelated package-lock.json churn from npm install was reverted, so the diff is only those two files.

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[cla-assistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}