Add Bernstein to Frameworks

[chernistry]

Adds Bernstein to the Frameworks section, alphabetically between Bee Agent Framework and CAMEL.

• Repo: https://github.com/sipyourdrink-ltd/bernstein
• License: Apache-2.0
• 350 stars, on PyPI as `bernstein`.
• Python orchestrator for 40+ CLI coding agents (Claude Code, Codex, Gemini CLI, Cursor, Aider). One LLM plan call up front; then deterministic scheduling, parallel git worktrees, quality gates, and an HMAC-chained audit log.

Maintainer disclosure: I am the maintainer.