docs(integrations/openclaw): add configuration guides

[XnLemon]

Which issue or RFC does this PR close?

Part of #1317.

Rationale for this change

OpenClaw is already supported by the CLI and integration code, but it lacks dedicated usage documentation. The integration was merged after v0.0.2, so the guide currently references master rather than that release tag.

What changes are included in this PR?

• Add an English OpenClaw configuration how-to guide.
• Add a Chinese OpenClaw configuration how-to guide.
• Document plugin setup, Server startup, scope modes, memory tools, authentication, verification, and disabling the integration.
• Explain why v0.0.2 cannot be used with setup openclaw.
• Recommend publishing a new tag containing the OpenClaw integration, after which the guide can use that tag instead of master.

Are there any user-facing changes?

Yes. This PR adds documentation for configuring the existing OpenClaw integration.

There are no runtime, API, persistence, or CLI behavior changes.

How was this change tested?

• make docs-test
• git diff --check

[XnLemon]

OpenClaw is already supported by the CLI and integration code, but it lacks dedicated usage documentation. The integration was merged after v0.0.2, so the guide currently references master rather than that release tag.

Pls pay attention to this. no README.md change.