docs(mcp): add Bitget-AI/agent-cli and Bitget-AI/agent-skill

[lukeGao0]

Repo URL(s):

• https://github.com/Bitget-AI/agent-cli
• https://github.com/Bitget-AI/agent-skill

Pillar & category:

• MCPs > Brokerage / exchange trading (agent-cli)
• Skills > Crypto / DeFi / on-chain (agent-skill)

Entry bullet(s):

• Bitget-AI/agent-cli - Bitget's official terminal AI trading tool (bgc) wrapping the Bitget UTA v3 API across market, trade, account, funds, subaccount, loan, and tax domains, with dry-run, read-only, confirm, and paper-trading safety flags.
• Bitget-AI/agent-skill - Bitget's official AI trading skill file giving Claude Code, Codex, and OpenClaw the judgment to invoke bgc (Bitget-AI/agent-cli) safely, shipped as pure Markdown with no runtime or API key required.

Submission checklist:

• Entries placed in the most specific existing category
• Description is a single sentence ending with punctuation
• Links are not already listed elsewhere in the README
• Both repos are official Bitget-AI first-party projects (exchange-official exception to the 100-star floor)

Bilingual symmetric edit:

• README.md and README.zh-CN.md updated in the same position, same order, same commit

Self-evaluation against quality bar:
Both repos are official, first-party Bitget tooling that fill a gap in the existing Brokerage/Skills sections — agent-cli is a dedicated terminal trading tool (distinct from the existing Bitget-AI/agent_hub-style MCP servers), and agent-skill is the companion skill file that teaches an agent when to invoke it safely.