doc: fix remaining broken docs.nvidia.com links in root README

Please also confirm the following

• I have searched the main issue tracker of NeMo Guardrails repository and believe that this is not a duplicate

Issue Kind

Error in existing documentation

Existing Link

https://github.com/NVIDIA-NeMo/Guardrails/blob/develop/README.md

Description

Six links in the root README point to old docs.nvidia.com paths that return 404 (checked with curl -L on 2026-09-20):

• Colang 2.0 Documentation: /colang-2/overview.html
• built-in guardrails and Guardrails Library documentation (two occurrences): /user-guides/guardrails-library.html
• using Docker: /user-guides/advanced/using-docker.html
• LangChain Integration Documentation: /user-guides/langchain/langchain-integration.html
• Security Guidelines: /security/guidelines.html
• docs/telemetry.md: /latest/telemetry.html

The docs site was reorganized. The equivalent live pages, each returning 200 with a matching page title, are:

• /configure-guardrails/colang/colang-2 (Colang 2.0 Guide)
• /configure-guardrails/guardrail-catalog (Guardrail Catalog)
• /more-deployment-options/using-docker (Deploy the NeMo Guardrails Library with Docker)
• /integration-with-third-party-libraries/langchain/langchain-integration (LangChain Integration)
• /resources/guidelines (Security Guidelines for LLM Integrations)
• /resources/telemetry (Telemetry)

The Getting Started Guide link is not included here; it is tracked in #2381.

AI assistance: I used Claude Code to find the replacement URLs and draft this text. I reviewed it and checked every link myself.